Almfeldt, M.W., author
W.M.C. Brown, 1967
Buku Teks
Rising, James S., author
Brown, 1964
Buku Teks
Edwards, Brian, author
Taylor & Francis Group, 2008
Buku Teks
Rockport Publishers,, 1996
Buku Teks
Yee, Rendow, author
John Wiley & Sons, 1997
Buku Teks