pdf file A history of central sets (to appear in Ergodic Theory and Dynamical Systems)

pdf file Notions of size in a semigroup -- an update from a historical perspective (to appear in Semigroup Forum)

pdf file The research of seven students at Howard University (to appear in Contemporary Mathematics)

pdf file (With W. Brian) Factoring a minimal ultrafilter into a thick part and a syndetic part

pdf file (With D. Strauss and L. Zamboni) Combining extensions of the Hales-Jewett Theorem with Ramsey Theory in other structures

pdf file (With K. Pleasant) Central Sets Theorem for arbitrary adequate partial semigroups

pdf file (With D. Strauss) Some new results about the ubiquitous semigroup H