["With paper, pencil, and slide rule." Cancer specialist Hermann Druckrey in internment camp Hammelburg (1946-1947)].

After World War II, Hermann Druckrey and Karl Küpfmüller spent many months in allied internment camps in Germany. In camp Hammelburg, the scholars formed a research collaboration which resulted in two very important publications. Druckrey informed Adolf Butenandt about the co-operation in personal letters which have recently become accessible. Through this new source, the origins of the Druckrey-Küpfmüller papers of 1948-1949 have been confirmed and some further details have been added.