Schwebel, Stephen M.
Grotius Publications, 1994
Buku Teks
Wootton, Barbara
Macmillan, 1992
Buku Teks
Pike, Kenneth L. (Kenneth Lee), 1912-2000, author
Mouton, 1972
Buku Teks
compiled and with commentary by Teresa Balough
University of Western Australia, 1982
Buku Teks
Engels, Frederick
Foreign Languages Publishing House, 1958
Buku Teks