Fisher, Douglas
Richard D. Irwin , 1980
Buku Teks SO
Kent, Raymond P.
Holt, Rinehart & Winston, 1947
Buku Teks SO
Klise, Eugene S.
South-Western College Publishing, 1972
Buku Teks SO
Kent, Raymond P.
Holt, Rinehart & Winston, [Date of publication not identified]
Buku Teks SO
Miller, Roger LeRoy
McGraw-Hill, 1993
Buku Teks SO