3-Manifolds:

C. Delman and R. Roberts, Alternating knots satisfy property P,
Comment. Math. Helv. 74 (1999), 376-397.

C. Delman, Essential laminations and Dehn surgery on 2-bridge knots,
Topology and its Applications, 63 (1995), 201-221

Dynamical Systems:

C. Delman and G. Galperin, Billiards with pockets: A separation principle and bound on the number of orbit types, Commun. Math. Phys. 230 (2002), 463-483.

Geometry:

C. Delman and G. Galperin, A tale of three circles, Mathematics Magazine 76 (2003), No. 1, 15-32.

(See also the related cover illustration from Mathematics Magazine, Vol. 76, No. 1.)