Balmer, Randall, author
Baylor University Press, 2016
Buku Teks
Tocqueville, Alexis De, author
David Campbell Publishers, 1994
Buku Referensi
Audubon, John James, author
Macmillan, 1985
Buku Referensi
edited by Eduardo P. Archetti
MacMillan Education, 1987
Buku Teks
Crockatt, Richard, author
Routledge, 2003
Buku Teks