A. Senfft, "Ethnographische Beiträge über die Karolineninsel Yap," Petermanns Mitteilungen, xlix. p. 53; id., "Die Rechtssitten der Jap-Eingeborenen," Globus, xci. pp. 142 sq.. Dr. C.G. Seligmann, in Journal of the Anthropological Institute, xxix. pp. 212 sq.; id., in Reports of the Cambridge Anthropological Expedition to Torres Straits, v. Dr.