Parkinson, C. Northcote (Cyril Northcote), 1909-1993, author
Federal Publications, 1992
Buku Teks
Etzel, Michael J., author
McGraw-Hill, 2004
Buku Teks
Phillips, Charles F., author
Boston , Houghton Mifflin
Buku Teks
Pratjihno, author
Djambatan, 1985
Buku Teks
Keegan, Warren J., author
Pearson, 2011
Buku Teks