Wiskemann, Elizabeth, author
Harper & Row , 1966
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
Longman, 1995
Buku Teks