In June 1941, Riewe co-authored a paper electron optics and plasma physics with the nuclear physicist Fritz Houtermans. At this time, Houtermans was known to have been at the Forschungslaboratoriums für Elektronenphysik (Research Laboratory for Electron Physics), a private laboratory of Manfred von Ardenne, in Berlin-Lichterfelde. The paper cites the two as being at a facility in Berlin; other papers by Riewe, three years earlier (see below), cited him as being at a facility in the community of Berlin-Wilmersdorf, which is in the vicinity of Berlin-Lichterfelde.