Johnstone, Ronald L., author
Prentice-Hall, 1975
Buku Teks
Burr, Nelson R., author
Princeton University Press,, 1961
Buku Teks
Weber, Max, 1864-1920, author
Beacon Press , 1963
Buku Teks
Olmstead, Clifton E., author
Prentice-Hall, 1960
Buku Teks
edited by James Ward Smith and A. Leland Jamison
Princeton University Press, 1961
Buku Teks