Über die multiplikative Translationsgleichung und idempotente Potenzreihenvektoren. Detlef Gronau — 1985 Aequationes mathematicae
Two iterative functional equations for power series. (Short Communication). Detlef Gronau — 1982 Aequationes mathematicae
Ludwig Reich on the occasion of his 60th birthday. An appreciation. (Ludwig Reich zum 60. Geburtstag. Eine Würdigung.) Gronau, Detlef — 2000 Mathematica Pannonica
Geometrical convexity and generalizations of the Bohr-Mollerup theorem on the gamma function. Gronau, Detlef; Matkowski, Janusz — 1993 Mathematica Pannonica