Unretractive and S-unretractive joins and lexicographic products of graphs. - Ulrich Knauer (J. Graph Theory, 1987)

Endomorphism spectra of graphs. - Michael Böttcher; Ulrich Knauer (Discret. Math., 1992)

Modellierung in der Ausbildung (von Mathematikern/Informatikern?) (Positionspapier). - Ulrich Knauer (Modellierung, 2001)

Postscript: "Endomorphism spectra of graphs" [Discrete Mathematics 109 (1992) 45-57]. - Michael Böttcher; Ulrich Knauer (Discret. Math., 2003)

Preface and Introduction. - Roland H. Kaschek; Ulrich Knauer (Electron. Notes Discret. Math., 2005)

Characterizations of Clifford semigroup digraphs. - Sayan Panma; N. Na Chiangmai; Ulrich Knauer; Sr. Arworn (Discret. Math., 2006)

Locally strong endomorphisms of paths. - Srichan Arworn; Ulrich Knauer; Sorasak Leeratanavalee (Discret. Math., 2008)

Preface. - Ulrich Knauer; Roland H. Kaschek (Discret. Math., 2009)

The congruence classes of paths and cycles. - Martin A. Michels; Ulrich Knauer (Discret. Math., 2009)

On transitive Cayley graphs of strong semilattices of right (left) groups. - Sayan Panma; Ulrich Knauer; Sr. Arworn (Discret. Math., 2009)

Completely Regular Endomorphisms of Split Graphs. - Ulrich Knauer; Apirat Wanichsombat (Ars Comb., 2014)