Brace, Richard M., author
Holt, Rinehart and Winston, 1961
Buku Referensi
Cambridge University Press, 1965
Buku Teks
Snyder, Louis L., author
D. van Nastrand Company, Inc., 1967
Buku Teks
Bertens, K. (Kees), author
Daras, 2005
Buku Teks
Mayer, Frederick, author
American Book Company, 1951
Buku Klasik