Ruiter, Dick W. P., author
Kluwer Academic, 2001
Buku Teks
Rose, Peter S., author
Business Publications, 1980
Buku Teks
Alpern, Andrew
McGraw-Hill, 1975
Buku Teks
Markus, Andrew, author
Allen & Unwin , 1990
Buku Teks
Sharp, Andrew
Clarendon Press, 1963
Buku Teks