edited by Vergilius Ferm
Philosophical Library, 1945
Buku Referensi
Farrington, Karen, author
Chancellor Pres, 1998
Buku Referensi
Weber, Max, 1864-1920, author
Beacon Press , 1963
Buku Teks
Johnstone, Ronald L., author
Prentice-Hall, 1975
Buku Teks
Turner, Bryan S., author
Sage, 1983
Buku Teks