edited by Mark Collins ; foreword by David Attenborough
Oxford University Press, 1990
Buku Teks
Simanjuntak, Emasta E., author
Universitas HKBP Nonmensen, 2018
Artikel Jurnal
Mamoto, Retno Sukardan, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1976
UI - Skripsi (Membership)
Veevers-Carter, W., author
Oxford University Press , 1984
Buku Teks
Francis, W.D., author
Australian Government Publishing Service, 1981
Buku Teks