edited by P. Edward Haley, David M. Keithly, and Jack Merritt
Westview Press, 1985
Buku Teks
Lieuwen, Edwin
Frederick A. Praeger, 1960
Buku Teks SO
Robin, Ranger
Gage, 1979
Buku Teks SO
Pierre, Andrew J.
Princeton University Press, 1982
Buku Teks SO
Edward, David V.
Holt, Rinehart and Winston, 1969
Buku Teks SO