McWilliams, Wayne C., author
Adamantine Press, 1990
Buku Teks
Palmer, R.R. (Robert Roswell), 1909-2002, author
McGraw-Hill, 1992
Buku Teks
Malchow, Howard L., author
Bloomsbury Academic, an imprint of Bloomsbury Pub, 2016
Buku Teks
Stavrianos, L.S.
Prentice-Hall, 1982
Buku Teks
Cook, Chris, author
Longman, 1991
Buku Referensi