Siemons, Johannes (1988) Centralizer algebras for an automorphism group of a finite incidence structure. Rendiconti del Seminario Matematico e Fisico di Milano, 56 (1). pp. 9-12. ISSN 0370-7377
Siemons, Johannes and Wagner, Ascher (1988) On the relationship between the lengths of orbits on k-sets and (k + l)-sets. Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg, 58 (1). pp. 267-274. ISSN 0025-5858
Siemons, Johannes (1988) Set and sequence closure for finite permutation groups. In: Combinatorics '86 (Trento, 1986). Ann. Discrete Math., 37 . North Holland, Amsterdam, pp. 413-419.