University of Denver Press,, 1951
Buku Teks
Walker, Bryce S., author
Time-Life Books, 1973
Buku Teks
Hurtig Publishers, 1984
Buku Teks
Macmillan, 1937
Buku Teks
Rivo Adikusuma, author
Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 2019
UI - Skripsi (Membership)