After his Ph.D., Ryser spent a year at Princeton's
Institute for Advanced Study, then joined the faculty of
Ohio State University. In 1962 he took a professorship at
Syracuse University, and in 1967 moved to
Caltech. His doctoral students include
Richard A. Brualdi,
Clement W. H. Lam, and
Marion Tinsley. Ryser contributed to the theory of
combinatorial designs, finite
set systems, the
permanent, combinatorial functions, and to many other topics in combinatorics. The
Journal of Combinatorial Theory, Series A denoted two issues after Ryser's passing as the "Herbert J. Ryser Memorial Issue", parts 1 and 2. ==Books==