edited by Mary Emanoil
Gale Research Inc., 1994
Buku Referensi
Washington National Academy Press , 1995
Buku Teks
Leigh, John
National Park and Wildlife Service, 1979
Buku Teks
disusun oleh Syahrial Anhar Harahap
Departemen Kehutanan , 2008
Buku Teks
Della Rizky Marsa Velesnika, author
Universitas Indonesia, 2016
UI - Tesis (Membership)