The University of Michigan, 1976
Buku Teks
Butwell, Richard
Frederick A. Praeger, 1962
Buku Teks
Butwell, Richard
Praeger Publishers, 1969
Buku Teks
edited by Derek Johnson and Mark Valenciaand"
ISEAS, 2005
Buku Teks
Butwell, Richard
Praeger, 1961
Buku Teks