Manus-Hannaford, R.G., author
Macdonald, 1964
Buku Teks
Norris, James S., author
Prentice-Hall, 1982
Buku Teks
Jenks, Ernest E., author
Alexander hamilton Institute, 1962
Buku Teks
Baduara S, Satar
Akademika Pressindo, 1984
Buku Teks
Baduara S, Satar
Akademika Pressindo, 1984
Buku Teks