Quinn, Daniel
Three Rivers Press, 1999
Buku Teks
Waddington, C.H., author
ST. Martin Press, 1978
Buku Teks
Bates, Daniel G.
McGraw-Hill, 1991
Buku Teks
Campbell, B. M. S., author.
Cambridge University Press , 2016
Buku Teks
Naisbitt, John, author
Brealey, 1994
Buku Teks