pdf file Recent results on partition regularity of infinite matrices (to appear in Connections in Discrete Mathematics, Cambridge University Press)

pdf file (With D. Strauss and L. Zamboni) Recurrence in the dynamical system (X,(T_s)_{s in S}) and ideals of beta S (to appear in Indagationes Mathematicae)

pdf file (With K. Pleasant) Preserving integer images of matrices (to appear in Integers)

pdf file A history of central sets

pdf file (With D. Strauss) Image partition regularity of matrices over commutative semigroups

pdf file Research of Wis Comfort on ultrafilters and the Stone-Cech compactification

pdf file (With L. Jones and D. Strauss) The relationships among many notions of largeness for subsets of a semigroup