Westerfield, Ray B., author
Roland Press , 1947
Buku Teks
Kent, Raymond P., author
Holt, Rinehart & Winston, 1947
Buku Teks
Klise, Eugene S., author
South-Western College Publishing, 1972
Buku Teks
Kent, Raymond P., author
Holt, Rinehart & Winston, [Date of publication not identified]
Buku Teks
Kreps, Cliften H., author
Ronald Press, 1967
Buku Teks