Artikel Jurnal
King, Kenneth, author
Longmann Group, 1991
Buku Teks
edited by S. Radhakrishna
Pergamon Press, 1980
Buku Teks
edited by Cleland, John; Ferry, Benoit [edited] (change)
The Falmer Press, 1995
Buku Teks
Bryant, John
Cornel Univ. Press, 1969
Buku Teks