Ovals.
O'Keefe, Christine M.; Penttila, Tim Hyperovals in ${\rm PG}(2,16)$. European J. Combin. 12 (1991), no. 1, 51--59.
O'Keefe, Christine M.; Penttila, Tim Polynomials for hyperovals of Desarguesian planes. J. Austral. Math. Soc. Ser. A 51 (1991), no. 3, 436--447.
O'Keefe, Christine M.; Penttila, Tim; Praeger, Cheryl E. Stabilisers of hyperovals in ${\rm PG}(2,32)$. Advances in finite geometries and designs (Chelwood Gate, 1990), 337--351, Oxford Sci. Publ., Oxford Univ. Press, New York, 1991.
O'Keefe, Christine M.; Pascasio, Arlene A.; Penttila, Tim Hyperovals in Hall planes. European J. Combin. 13 (1992), no. 3, 195--199.
O'Keefe, Christine M.; Penttila, Tim A new hyperoval in ${\rm PG}(2,32)$. J. Geom. 44 (1992), no. 1-2, 117--139.
O'Keefe, Christine M.; Penttila, Tim Symmetries of arcs. J. Combin. Theory Ser. A 66 (1994), no. 1, 53--67.
Penttila, Tim; Royle, Gordon F. Classification of hyperovals in ${\rm PG}(2,32)$. J. Geom. 50 (1994), no. 1-2, 151--158.
Penttila, Tim; Pinneri, Ivano Irregular hyperovals in ${\rm PG}(2,64)$. J. Geom. 51 (1994), no. 1-2, 89--100.
Payne, S. E.; Penttila, Tim; Pinneri, Ivano Isomorphisms between Subiaco $q$-clan geometries. Bull. Belg. Math. Soc. Simon Stevin 2 (1995), no. 2, 197--222.
Penttila, Tim; Royle, Gordon F.; Simpson, Michael K. Hyperovals in the known projective planes of order $16$. J. Combin. Des. 4 (1996), no. 1, 59--65.
Penttila, Tim; Royle, Gordon F. On hyperovals in small projective planes. J. Geom. 54 (1995), no. 1-2, 91--104.
Cherowitzo, W.; Penttila, T.; Pinneri, I.; Royle, G. F. Flocks and ovals. Geom. Dedicata 60 (1996), no. 1, 17--37.
Payne, S. E.; Penttila, Tim; Royle, Gordon F. Building a cyclic $q$-clan. Mostly finite geometries (Iowa City, IA, 1996), 365--378, Lecture Notes in Pure and Appl. Math., 190, Dekker, New York, 1997.
Penttila, Tim; Pinneri, Ivano Hyperovals. Australas. J. Combin. 19 (1999), 101--114.
Cherowitzo, William E.;O'Keefe, Christine M;Penttila, Tim Unified construction of finite geometries in characteristic 2, submitted.
Ovoids.
O'Keefe, Christine M.; Penttila, Tim Ovoids of ${\rm PG}(3,16)$ are elliptic quadrics. J. Geom. 38 (1990), no. 1-2, 95--106.
O'Keefe, Christine M.; Penttila, Tim Ovoids of ${\rm PG}(3,16)$ are elliptic quadrics. II. J. Geom. 44 (1992), no. 1-2, 140--159.
O'Keefe, Christine M.; Penttila, Tim; Royle, Gordon F. Classification of ovoids in ${\rm PG}(3,32)$. J. Geom. 50 (1994), no. 1-2, 143--150.
Glynn, David G.; O'Keefe, Christine M.; Penttila, Tim; Praeger, Cheryl E. Ovoids and monomial ovals. Geom. Dedicata 59 (1996), no. 3, 223--241.
O'Keefe, Christine M.; Penttila, Tim Ovoids with a pencil of translation ovals. Geom. Dedicata 62 (1996), no. 1, 19--34.
O'Keefe, Christine M.; Penttila, Tim Ovals in translation hyperovals and ovoids. European J. Combin. 18 (1997), no. 6, 667--683.
Penttila, Tim; Praeger, Cheryl E. Ovoids and translation ovals. J. London Math. Soc. (2) 56 (1997), no. 3, 607--624.
Penttila, Tim A plane representation of ovoids. Util. Math. 56 (1999), 245--250.
Brown, Matthew R.; O'Keefe, Christine M.; Penttila, Tim Triads, flocks of conics and $Q\sp -(5,q)$. Designs and codes---a memorial tribute to Ed Assmus. Des. Codes Cryptogr. 18 (1999), no. 1-3, 63--70.
Flocks.
Payne, S. E.; Penttila, Tim; Pinneri, Ivano Isomorphisms between Subiaco $q$-clan geometries. Bull. Belg. Math. Soc. Simon Stevin 2 (1995), no. 2, 197--222.
Penttila, Tim; Royle, Gordon F. On hyperovals in small projective planes. J. Geom. 54 (1995), no. 1-2, 91--104.
Cherowitzo, W.; Penttila, T.; Pinneri, I.; Royle, G. F. Flocks and ovals. Geom. Dedicata 60 (1996), no. 1, 17--37.
Payne, S. E.; Penttila, Tim; Royle, Gordon F. Building a cyclic $q$-clan. Mostly finite geometries (Iowa City, IA, 1996), 365--378, Lecture Notes in Pure and Appl. Math., 190, Dekker, New York, 1997.
Penttila, Tim; Storme, L. Monomial flocks and herds containing a monomial oval. J. Combin. Theory Ser. A 83 (1998), no. 1, 21--41.
Penttila, Tim; Royle, Gordon F. BLT-sets over small fields. Australas. J. Combin. 17 (1998), 295--307.
Penttila, T. Regular cyclic BLT-sets. Combinatorics '98 (Mondello). Rend. Circ. Mat. Palermo (2) Suppl. No. 53 (1998), 167--172.
O'Keefe, Christine M.; Penttila, Tim Characterisations of flock quadrangles. Geom. Dedicata 82 (2000), no. 1-3, 171--191.
Law, Maska;Penttila Tim Flocks, ovals and generalised quadrangles. Four lectures in Napoli, June, 2000 (with M. Law), Universita degli Studi di Napoli, September, 2000.Research Report UWA September 2000/15. Preprint n. 40(2000), pubblicazioni del Dipartimento di Matematica e applicazioni "R. Cacciopoli",Universita degli Studi di Napoli "Federico II".
Cherowitzo, William E.;O'Keefe, Christine M;Penttila, Tim Unified construction of finite geometries in characteristic 2, submitted.
Baker,R.D.; Ebert,G.;Penttila, T Hyperbolic fibrations and q-clans, in preparation.
Bader,L;O'Keefe,C.M.;Penttila,T Some remarks on flocks, submitted.
Law,Maska;Penttila Tim Some flocks in characteristic 3, J. Combin. Th. (A), to appear
Bader,L;Ghinelli,D.;Penttila,T.; On monomial flocks, Europ. J. Combin.,submitted.
Law,Maska;Penttila Tim BLT-sets over small fields, II , in preparation.
Generalised quadrangles.
O'Keefe, Christine M.; Penttila, Tim Elation generalized quadrangles of order $(q\sp 2,q)$. Geometry, combinatorial designs and related structures (Spetses, 1996), 181--192, London Math. Soc. Lecture Note Ser., 245, Cambridge Univ. Press, Cambridge, 1997.
Penttila, Tim; Williams, Blair Ovoids of parabolic spaces. Geom. Dedicata 82 (2000), no. 1-3, 1--19.
Subquadrangles of generalized quadrangles of order (q^2,q), q even, (with C.M.O'Keefe), J. Combin. Th. (A).
Translation generalised quadrangles and elation Laguerre planes of order 16, European J. Combin.
Eggs and translation generalized quadrangles, (with M. Lavrauw), J. Combin. Th. (A).
Automorphism groups of generalised quadrangles via an unusual action of PGammaL(2,2^h), (with C.M.O'Keefe)
Spreads of T_2(O), generalised fans and alpha-flocks (with M.Brown, C.M.O'Keefe, S.E.Payne, G.F.Royle)
Projective planes.
Penttila, Tim; Williams, Blair Regular packings of ${\rm PG}(3,q)$. European J. Combin. 19 (1998), no. 6, 713--720.