Wolters, O. W. (Oliver William), author
Cornell University Press, 1970
Buku Teks
Davison, Graeme
Melbourne University Press , 1979
Buku Teks
Hare, Bill, author
[American Management Association, ], 2004
eBooks
Frankland, Mark, author
Institution of Engineering and Technology, 2002
eBooks
Vaillant, George C., author
Penguin Books, 1950
Buku Teks