Brandt, Conrad
George Allen and Unwin, 1959
Buku Teks SO
edited by Richard Hofstadter and Wilson Smith
University of Chicago Press, 1961
Buku Teks
edited, Nathan Reingold; edited, Ida H. Reingold
University of Chicago Press, 1981
Buku Referensi
Welch, David
Heinemann, 1994
Buku Teks
Schwartz, Bernard
McGraw-Hill, 1971
Buku Teks