Hodgson, Peter Edward, author
Clarendo Press, 1997
Buku Teks
Green, Alex Edward Samuel, 1919-, author
McGraw-Hill, 1955
Buku Teks
Kaplan, Irving, author
Addison-Wesley, 1963
Buku Teks
Kaplan, Irving, author
Addison-Wesley, 1964
Buku Teks
Burcham, W.E.
Longman , 1978
Buku Teks