Fisher, Janet
Scolar Press, 1994
Buku Referensi
Woodford, A.O.
W.H. Freeman, 1965
Buku Teks
Lehmann, Winfred P.
Holt, Rinehart and Winston, 1962
Buku Teks SO
East, W. Gordon
E.P. Dutton, 1950
Buku Teks SO
Shepperd, William R.
Barnes and Noble, 1959
Buku Referensi