Van Leijenhorst, D. C. A combinatorial proof of a theorem by F. A. Grunbaum on sets of differences - Nijmegen : Catholic University, Department of Mathematics, 1979 - 1p. ; 21cm. - Report 7920 . Subjects--Topical Terms: Combinatorial analysisCombinatorial set theoryDifference sets LC Class. No.: QA3.R46 no.7920