Raven, Peter H.
Worth Publisher, 1986
Buku Referensi
Corner, E.J.H
World Publishing, 1964
Buku Teks SO
Laetsch, Watson M.
Little, Brown, 1979
Buku Teks SO
Raven, Peter H.
Worth Publishers, 1992
Buku Teks SO
Kaufman, Peter B.; Carlson, Thomas F.; Dayanandan, P.; Evans, Michael L.; Fisher, Jack B.; Parks, Clifford; Wells, James R.
Harper & Row, 1989
Buku Referensi