pdf file (With I. Leader and D. Strauss) Pairwise sums in colourings of the reals (to appear in Abh. Math. Sem. Univ. Hamburg)

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) Infinite compact sets of idempotents in beta S (to appear in Semigroup Forum)

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 D. Strauss) Long increasing chains of idempotents in beta G (to appear in Fund. Math.)

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