Phelps, Edmund S.
Norton , 1962
Buku Teks
Phelps, Edmund S.
Orton & Co , 1962
Buku Teks
Weisbrod, Burton A.
University of California Press, 1978
Buku Teks
edited by Christopher G. Reddick, Jerrell D. Coggburn
CRC Press, 2008
Buku Referensi
edited by Edwin S. Mills and John F. McDonald ; Mary L. McLean, associate editor
Transaction Publishers, 1992
Buku Teks