Rolph, Earl R.
N.Y. The Ronald Press , 1961
Buku Teks
Rolph, Earl R.
University of California Press, 1956
Buku Teks
Hicks, Ursula K., author
Kinokuniya , 1959
Buku Teks
Rosen, Harvey S., author
McGraw-Hill, 2010
Buku Teks
edited by Carl S. Shoup
Aldine Publishing, 1969
Buku Teks