Reisebilder aus Liberia: Resultate geographischer, naturwissenschaftlicher und ethnographischer untersuchungen während der jahre 1879-1882 und 1886-1887. 2 vols.

The first comprehensive monograph on the Republic of Liberia, published 50 years after its colonization by freed American slaves and their descendents. Digital facsimile from the Internet Archive at this link. Translated into English and edited by Henk Dop and Phillip T. Robinson as Travel Sketches from Liberia. Johann Büttikofer's 19th century rainforest explorations in West Africa. (Leiden: Brill, 2013).