Adams, Henry
Prentice-Hall, 1963
Buku Teks
Risjord, Norman K.
Prentice-Hall, 1985
Buku Teks
Parkes, Henry Bamford
Alfred A. Knoft, 1968.
Buku Teks
Cassara, Ernestt
Gale Research Coompany, 1977
Buku Teks
Risjord, Norman K.
Prentice-Hall, 1985
Buku Teks