Naber, Gregory L., author
Springer, 2012
eBooks
Salaman, Redclife N., author
Cambridge University Press, 2014
Buku Teks
Cox, Brian
Athenaeum Press, 1999
Buku Teks
Anderson, John D.
McGraw-Hill, 1985
Buku Teks
Oakland, John, author
Routledge , 1992
Buku Teks