Home › Authors › Richard G. Zweifel 👤 Richard G. Zweifel b. 1926 – d. 2019 · 2 books Books by Richard G. Zweifel Results of the Puritan-America Results of the Puritan-American Museum of Natural History expedition to Western Mexico 1959 Frogs of the Papuan Hylid genu Frogs of the Papuan Hylid genus Nyctimystes 1958