Dean, Howard H.
Prentice-Hall, 1962
Buku Teks
Bramer, George R., author
Charles E. Merrill Publishing Company, 1981
Buku Teks
Tyner, Thomas E.
Wadsworth, 1985
Koleksi Publik
Tyner, Thomas E.
Wadsworth, 1985
Buku Teks
Harris, Muriel, author
Prentice-Hall, 1997
Buku Referensi