Armstrong, Bruce K., author
Oxford University Press, 1994
Buku Teks
edited by Kyle Steenland
Oxford University Press, 1993
Buku Teks
Morton, Richard F., 1924-, author
Aspen, 1990
Buku Teks
edited by Barrie M. Margetts and Michael Nelson
Oxford University Press, 1991
Buku Teks
Armstrong, Bruce K., author
Oxford University Press, 1994
Buku Referensi