Sabine, George H., author
George G. Harrap, 1959
Buku Teks
Sabine, George H., author
Henry Holt , 1954
Buku Teks
McGee, R. Jon, author
McGraw-Hill, 2012
Buku Referensi
edited by Alice Horning and Anne Becker
Parlor Press, 2006
Buku Teks
Sabine, George H., author
Harcourt Brace College Publishers, 1973
Buku Teks