Personal Communication - What is Beyond Radio? - Norbert Niebert; Eckhard Geulen (IS&N, 1994)

Services and applications: requirements and realizations in the UMTS era. - Alistair Munro; Eckhard Geulen; Michel Deguine; Giuseppe Melpignano; Ana Martínez (IEEE Commun. Mag., 1998)

Any network, any terminal, anywhere [cellular radio]. - Andreas Fasbender; Frank Reichert; Eckhard Geulen; Johan Hjelm; Thomas Wierlemann (IEEE Wirel. Commun., 1999)