Skidmore, Thomas E., author
Oxford University Press, 2001
Buku Teks
Skidmore, Thomas E., author
Oxford University Press, 1984
Buku Teks
Joseph Maier, Richard W.Weatherhead
F. A. Praeger, 1964
Buku Teks
edited by Fredrick B. Pike
University of Notre Dame Press, 1959
Buku Teks
edited by David Collier
Princeton University Press, 1979
Buku Teks