Padgett, Stephen
Longman, 1991
Buku Teks
Oxford University Press , 1996
Buku Teks
Wiskemann, Elizabeth, author
Harper Taschbooks, 1966
Buku Teks
Anderson, M.S., author
Longman, 1971
Buku Teks
Ashley, Maurice, author
Frederick A. Praeger, 1969
Buku Teks