Several of my preprints can be found on the website of the Research Group Incidence Geometry.

• [1] De regel van Descartes. Wiskunde en Onderwijs 83 (1995), 300--304. (In dutch)
• [2] Near polygons from partial linear spaces. (with F. De Clerck) Geom. Dedicata 75 (1999), 287--300.
• [3] On linear representations of near hexagons. (with F. De Clerck) European J. Combin. 20 (1999), 45--60.
• [4] Generalized quadrangles with a spread of symmetry. European J. Combin. 20 (1999), 759--771.
• [5] On near hexagons and spreads of generalized quadrangles. J. Algebraic Combin. 11 (2000), 211--226.
• [6] On near-polygons and the Coxeter cap in $\mathrm{PG}(5,3)$. J. Geom. 68 (2000), 23--33.
• [7] On the number of nonisomorphic glued near hexagons. Bull. Belg. Math. Soc. Simon Stevin 7 (2000), 493--510.
• [8] Recent results on near polygons: a survey. pp 39--59 in Proceedings of the Academy Contact Forum, 20 october 2000, Brussels (F. De Clerck, L. Storme, J. A. Thas, H. Van Maldeghem, eds.), Universa Press, 2001.
• [9] Near hexagons with four points on a line. Adv. Geom. 1 (2001), 211--228.
• [10] Glued near polygons. European J. Combin. 22 (2001), 973--981.
• [11] Generalized quadrangles with a unique grid through every two intersecting lines. (with S. E. Payne) Bull. Inst. Combin. Appl. 35 (2002), 47--52.
• [12] On the uniqueness of near polygons with three points on every line. European J. Combin. 23 (2002), 523--528.
• [13] The glueing of near polygons. Bull. Belg. Math. Soc. Simon Stevin 9 (2002), 621--630.
• [14] Generalized quadrangles with a spread of symmetry and near polygons. (with K. Thas) Illinois J. Math. 46 (2002), 797--818.
• [15] Near polygons having a big sub near polygon isomorphic to $H_n$. Ann. Comb. 6 (2002), 285--294.
• [16] Welke rationale getallen liggen tussen twee gegeven rationale getallen?, Wiskunde en Onderwijs 113 (2003), 26--30. (In dutch)
• [17] Characterizations of near hexagons by means of one local space. J. Combin. Theory Ser. A 102 (2003), 283--292.
• [18] A thin near hexagon with 50 points. (With R. Blok and U. MeierFrankenfeld) J. Combin. Theory Ser. A 102 (2003), 293--308.
• [19] Two conjectures regarding dense near polygons with three points on each line. (with P. Vandecasteele) European J. Combin. 24 (2003), 631--647.
• [20] On the finiteness of near polygons with 3 points on every line. J. Algebraic Combin. 18 (2003), 41--46.
• [21] A new geometrical construction for the near hexagon with parameters $(s,t,T_2)=(2,5,\{ 1,2 \})$. J. Geom. 78 (2003), 50--58.
• [22] New near polygons from Hermitian varieties. Bull. Belg. Math. Soc. Simon Stevin 10 (2003), 561--577.
• [23] On a nice property of the sequence $x_{n+2}=x_{n+1}^3/(x_n^2-2x_{n+1}^2)$. Int. J. Appl. Math. 15 (2004), 159--163.
• [24] Decomposable near polygons. Ann. Comb. 8 (2004), 251--267.
• [25] Near polygons having a big sub near polygon isomorphic to $G_n$. Bull. Belg. Math. Soc. Simon Stevin 11 (2004), 321--341.
• [26] Near polygons with a nice chain of sub near polygons. (with P. Vandecasteele) J. Combin. Theory Ser. A 108 (2004), 297--311.
• [27] On a problem regarding the $n$-sectors of a triangle. Forum Geom. 5 (2005), 47--52.
• [28] Valuations of near polygons. (with P. Vandecasteele) Glasgow Math. J. 47 (2005), 347--361.
• [29] Slim near polygons. Des. Codes Cryptogr. 37 (2005), 263--280.
• [30] Valuations and hyperplanes of dual polar spaces. (with P. Vandecasteele) J. Combin. Theory Ser. A 112 (2005), 194--211.
• [31] The hyperplanes of DW(5,q) with no ovoidal quad. (with H. Pralle) Glasgow Math. J. 48 (2006), 75--82.
• [32] The valuations of the near hexagons related to the Witt-designs $S(5,6,12)$ and $S(5,8,24)$. (with P. Vandecasteele) J. Combin. Des. 14 (2006), 214--228.
• [33] Locally singular hyperplanes in thick dual polar spaces of rank 4. (with I. Cardinali and A. Pasini) J. Combin. Theory Ser. A 113 (2006), 636-646.
• [34] Near polygons having a big sub near polygon isomorphic to $H^D(2n-1,4)$. (with P. Vandecasteele) Ars Combin. 79 (2006), 47--64.
• [35] Bounding the size of near hexagons with lines of size 3. J. Graph Theory 52 (2006), 47--64.
• [36] Compatible spreads of symmetry in near polygons. J. Algebraic Combin. 23 (2006), 137--148
• [37] Near polygons with hexes of type $H^D(5,q^2)$, $Q(5,q) \times L_{q+1}$ or $Q(5,q) \otimes Q(5,q)$. J. Combin. Theory Ser. A 113 (2006), 762--778.
• [38] Near polygons. (263pp.) Frontiers in Mathematics, Birkhauser, Basel, 2006. ISBN:3-7643-7552-3.
• [39] Distance-j-ovoids in regular near 2d-gons. Graphs Combin. 22 (2006), 203--216.
• [40] The completion of the classification of the regular near octagons with thick quads. J. Algebraic Combin. 24 (2006), 23--29.
• [41] The distance-2-sets of the slim dense near hexagons. (with P. Vandecasteele) Ann. Comb. 10 (2006), 179--196.
• [42] Dense near polygons with two types of quads and three types of hexes. J. Combin. Math. Combin. Comput. 57 (2006), 113--128.
• [43] Generalized quadrangles of order $s$ with a hyperbolic line consisting of regular points. Electr. Notes Discrete Math. 26 (2006), 39--42
• [44] The simple connectedness of hyperplane complements in thick dual polar spaces of rank at least 4. (with I. Cardinali and A. Pasini) Electr. Notes Discrete Math. 26 (2006), 15--20.
• [45] A note on symplectic polar spaces over non-perfect fields of characteristic 2. (with A. Pasini) Electr. Notes Discrete Math. 26 (2006), 119--121.
• [46] The valuations of the near octagon $I_4$. (with P. Vandecasteele) Electron. J. Comb. 13, Research Paper R76, 23p. (2006).
• [47] The classification of the slim dense near octagons. (with P. Vandecasteele) European J. Combin. 28 (2007), 410--428.
• [48] Valuations of glued near hexagons. J. Combin. Des. 15 (2007), 35--48.
• [49] Minimal full polarized embeddings of dual polar spaces. (with I. Cardinali and A. Pasini) J. Algebraic Combin. 25 (2007), 7--23.
• [50] A characterization of the SDPS-hyperplanes of dual polar spaces. European J. Combin. 28 (2007), 705--714.
• [51] Dense near octagons with four points on each line, I. Ann. Comb. 11 (2007), 127--142.
• [52] The hyperplanes of DQ(2n,K) and DQ^-(2n+1,q) which arise from their spin-embedding. J. Combin. Theory Ser. A 114 (2007), 681--691.
• [53] A general theory for dense near polygons with a nice chain of subpolygons. European J. Combin. 28 (2007), 1395--1411.
• [54] The exceptional hyperplanes of DH(5,4). (with H. Pralle) European J. Combin. 28 (2007), 1412--1418.
• [55] Some notes on generalized quadrangles with a span of regular points. (with S. Payne) Beitr. Algebra Geom. 48 (2007), 49--58.
• [56] The universal embedding of the near polygon $G_n$. Electron. J. Combin. 14 (2007), Research paper 39, 12pp.
• [57] Sets of points in the half-spin geometry related to $Q^+(9,q)$. Linear Algebra Appl. 424 (2007), 480--491.
• [58] Dense near octagons with four points on each line, II. Adv. Geom. 7 (2007), 191--206.
• [59] On the hyperplanes of the half-spin geometries and the dual polar spaces $DQ(2n,K)$. J. Combin. Theory Ser. A 114 (2007), 979--992.
• [60] Minimal scattered sets and polarized embeddings of dual polar spaces. (with A. Pasini) European J. Combin. 28 (2007), 1890--1909.
• [61] Generating symplectic and hermitian dual polar spaces over arbitrary fields nonisomorphic to $\mathbb{F}_2$. (with A. Pasini) Electron. J. Combin. 14 (2007), Research paper 54, 17pp.
• [62] A decomposition of the natural embedding spaces for the symplectic dual polar spaces. Linear Algebra Appl. 426 (2007), 462--477.
• [63] On small and large hyperplanes of $DW(5,q)$. (with H. Pralle) Graphs Combin. 23 (2007), 367--380.
• [64] Hyperplanes of $DW(2n-1,q)$, $q \not= 2$, without ovoidal quads. Discrete Math. 307 (2007), 2680--2694.
• [65] The generating rank of the $U_4(3)$ near hexagon. Discrete Math. 307 (2007), 2900--2905.
• [66] Minimal underlying division rings of sets of points of a projective space. (with A. Pasini) J. Algebra 318 (2007), 641--652.
• [67] The valuations of the near octagon $\H_4$. (with P. Vandecasteele) Graphs Combin. 23 (2007), 601--623.
• [68] A coordinatization of generalized quadrangles with a regular spread. European J. Combin. 29 (2008), 242--253.
• [69] Isometric full embeddings of $DW(2n-1,q)$ into $DH(2n-1,q^2)$. Finite Fields Appl. 14 (2008), 188-200.
• [70] The structure of full embeddings of the symplectic and hermitian dual polar spaces. (with I. Cardinali) Adv. Geom. 8 (2008), 111--137.
• [71] The combinatorial properties of the hyperplanes of $DW(5,q)$ arising from embedding. (with B. Cooperstein) Des. Codes Cryptogr. 47 (2008), 35--51.
• [72] The structure of the spin-embeddings of dual polar spaces and related geometries European J. Combin. 29 (2008), 1242--1256.
• [73] A characterization of $m$-ovoids of polar spaces. (10pp.) Adv. Geom. 8 (2008), 367--375
• [74] Two classes of hyperplanes of dual polar spaces without subquadrangular quads. J. Combin. Theory Ser. A 115 (2008), 893--902.
• [75] The hyperplanes of DH(5,q^2). (with H. Pralle) Forum Math. 20 (2008), 239--264.
• [76] The uniqueness of the generalized quadrangle of order 5 with an axis of symmetry. Ars Combin. 88 (2008), 203--216.
• [77] Two new classes of hyperplanes of the dual polar space $DH(2n-1,4)$ not arising from the Grassmann-embedding. Linear Algebra Appl. 429 (2008), 2030--2045.
• [78] A recursive construction for the dual polar spaces $DQ(2n,2)$. Discrete Math. 308 (2008), 5504--5515.
• [79] The hyperplanes of the near hexagon on the 2-factors of the complete graph $K_8$. (with H. Pralle) Discrete Math. 308 (2008), 5656--5671.
• [80] On the Grasmann-embeddings of the Hermitian dual polar spaces. Linear Multilinear Algebra 56 (2008), 665--677.
• [81] Hyperplanes of embeddable Grassmannians arise from embeddings: a short proof. Linear Algebra Appl. 430 (2009), 418--422.
• [82] On the simple connectedness of hyperplane complements in dual polar spaces. (with I. Cardinali and A. Pasini) Discrete Math. 309 (2009), 294--303.
• [83] The hyperplanes of $DW(5,2^h)$ arising from embedding. Discrete Math. 309 (2009), 304--321.
• [84] On the nucleus of the Grassmann embedding of the symplectic dual polar space $DSp(2n,F)$, $char(F)=2$. (With R. J. Blok and I. Cardinali) European J. Combin. 30 (2009), 468--472.
• [85] On a class of hyperplanes of the symplectic and Hermitian dual polar spaces. Electron. J. Combin. 16 (2009), Research paper 1, 20pp.
• [86] An alternative definition of the notion valuation in the theory of near polygons. Electron. J. Combin. 16 (2009), Research paper 16, 14pp.
• [87] The uniqueness of the SDPS-set of the symplectic dual polar space $DW(4n-1,q)$, $n \geq 2$. European J. Combin. 30 (2009), 911--922.
• [88] On isometric full embeddings of symplectic dual polar spaces into Hermitian dual polar spaces. Linear Algebra Appl. 430 (2009), 2541--2552.
• [89] Some subspaces of the $k$-th exterior power of a symplectic vector space. Linear Algebra Appl. 430 (2009), 3095--3104.
• [90] On the intersection of distance-$j$-ovoids and subpolygons in generalized polygons. Discrete Math. 309 (2009), 3023--3031.
• [91] Points and hyperplanes of the universal embedding space of the dual polar space $DW(5,q)$, $q$ odd. (with B. N. Cooperstein) Michigan Math. J. 58 (2009), 195--212.
• [92] On symplectic polar spaces over non-perfect fields of characteristic 2. (with A. Pasini) Linear Multilinear Algebra 57 (2009), 567--575.
• [93] Coordinatization structures for generalized quadrangles. Advances in Mathematics Research 9, pp. 275--292. Nova Sci. Publ., New York, 2009.
• [94] Polarized and homogeneous embeddings of dual polar spaces. (with R. Blok, I. Cardinali and A. Pasini) J. Algebraic Combin. 30 (2009), 381--399.
• [95] Near hexagons with two possible orders for the quads. Ars Combin. 93 (2009), 225--240.
• [96] Hyperplanes of $DW(5,K)$ with $K$ a perfect field of characteristic 2. J. Algebraic Combin. 30 (2009), 567--584.
• [97] The valuations of the near polygon $\G_n$. Electron. J. Combin. 16 (2009), Research paper 137, 29pp.
• [98] Regular partitions of dual polar spaces. (with I. Cardinali) Linear Algebra Appl. 432 (2010), 744--769.
• [99] The valuations of the near octagon $G_4$. (with P. Vandecasteele) Discrete Math. 310 (2010), 755--766.
• [100] On geometric SDPS-sets of elliptic dual polar spaces. J. Combin. Theory Ser. A 117 (2010), 528--544.
• [101] On the Grassmann modules for the symplectic groups. J. Algebra 324 (2010), 218--230.
• [102] Direct constructions of hyperplanes of dual polar spaces arising from embeddings. Ann. Comb. 14 (2010), 193--209.
• [103] A note on near hexagons with lines of size 3. Ars Combin. 96 (2010), 263--273.
• [104] On hyperovals of polar spaces. Des. Codes Cryptogr. 56 (2010), 183--195.
• [105] Locally subquadrangular hyperplanes in symplectic and Hermitian dual polar spaces. European J. Combin. 31 (2010), 1586--1593.
• [106] Some subspaces of the projective space $PG(\bigwedge^k V)$ related to regular spreads of $PG(V)$. Electron. J. Linear Algebra 20 (2010), 354--366.
• [107] Intriguing sets of vertices of regular graphs. (with H. Suzuki) Graphs Combin. 26 (2010), 629--646.
• [108] The hyperplanes of the $U_4(3)$ near hexagon. (with S. V. Shpectorov) Graphs Combin. 26 (2010), 647--671.
• [109] The hyperplanes of $DQ^-(7,K)$ arising from embedding. Discrete Math. 310 (2010), 3149--3154.
• [110] On the Grassmann modules for the unitary groups. Linear Multilinear Algebra 58 (2010), 887--902.
• [111] A property of isometric mappings between dual polar spaces of type $DQ(2n,K)$. (16pp.) Ann. Comb. 14 (2010), 307--318.
• [112] The nonexistence of regular near octagons with parameters $(s,t,t_2,t_3)=(2,24,0,8)$. Electron. J. Combin. 17 (2010), Research paper 149, 10pp.
• [113] Non-abelian representations of the slim dense near hexagons on 81 and 243 points. (with B. K. Sahoo and N. S. N. Sastry) J. Algebraic Combin. 33 (2011), 127--140.
• [114] The valuations of the near 2n-gon I_n. Ars Combin. 98 (2011), 321--336.
• [115] On extensions of hyperplanes of dual polar spaces. J. Combin. Theory Ser. A. 118 (2011), 949--961.
• [116] Canonical equations for nonsingular quadrics and Hermitian varieties of Witt index at least $\frac{n-1}{2}$ of $\PG(n,K)$, $n$ odd. Int. Electron. J. Geom. 4 (2011), 48--69.
• [117] On the trivectors of a 6-dimensional symplectic vector space. Linear Algebra Appl. 435 (2011), 289--306.
• [118] Dense near octagons with four points on each line, III. Ann. Comb. 15 (2011), 19--35.
• [119] A note on the spin-embedding of the dual polar space $DQ^-(2n+1,K)$. Ars Combin. 99 (2011), 365--375.
• [120] On polyvectors of vector spaces and hyperplanes of projective Grassmannians. Linear Algebra Appl. 435 (2011), 1055--1084.
• [121] The hyperplanes of finite symplectic dual polar spaces which arise from projective embeddings. European J. Combin. 32 (2011), 1384--1393.
• [122] Hyperplanes and projective embeddings of dual polar spaces. J. Geom. 101 (2011), 115--129.
• [123] On sets of odd type of $PG(n,4)$ and the universal embedding of the dual polar space $DH(2n-1,4)$. Discrete Math. 312 (2012), 554-560.
• [124] Dual embeddings of dense near polygons. Ars Combin. 103 (2012), 33-54.
• [125] The universal embedding of the near hexagon related to the extended ternary Golay code. Discrete Math. 312 (2012), 883--890.
• [126] Spin-embeddings, two-intersection sets and two-weight codes. (with I. Cardinali) (11pp.) Ars Combinatoria, to appear.
• [127] Association schemes on the set of lines of regular near hexagons. (10pp.) Ars Combinatoria, to appear.
• [128] An alternative approach to the classification of the regular near hexagons with parameters $(s,t,t_2)=(2,11,1)$. (12pp.) Ars Combinatoria, to appear.
• [129] A decomposition of the universal embedding space for the near polygon H_n. (14 pp.) Designs, Codes and Cryptography, to appear.
• [130] Pseudo-embeddings and pseudo-hyperplanes. (26 pp.) Advances in Geometry, to appear.
• [131] Intriguing sets of points of $Q(2n,2) \setminus Q^+(2n-1,2)$. (15 pp.) Graphs and Combinatorics, to appear.
• [132] The pseudo-hyperplanes and homogeneous pseudo-embeddings of $AG(n,4)$ and $PG(n,4)$. (34 pp.) Designs, Codes and Cryptography, to appear.
• [133] The hyperplanes of the glued near hexagon $Q(5,2) \otimes Q(5,2)$. (17 pp.) Annals of Combinatorics, to appear.
• [134] Two-intersection sets as subsets of parabolic quadrics. (8 pp.) Ars Combin., to appear.