Drake, St. Clair
Harper and Row, 1962
Buku Teks
Ferriss, Hugh
Dover Publications, 2005
Buku Teks SO
Wolfe, Gerard R.
McGraw-Hill, 1994
Buku Referensi
edited by Robert Moore Fisher
Doubleday, 1955
Buku Teks SO
edited by Leonard J. Duhl, with the assistance of John Powell
Basic Books, 1963
Buku Teks SO