Ford, Michael J., author
George Allen and Unwin, 1982
Buku Teks
Wellburn, Alan
Addison-Wesley, 1996
Buku Teks
edited by Richard W. Battarbee, Heather A. Binney
Wiley-Blackwell, 2008
Buku Teks
Quinto, Cornel, author
Springer, 2012
eBooks
Friedman, Thomas L., author
Farrar, Straus and Giroux, 2008
Buku Teks