Boston: Houghton: 1993,
Buku Referensi
Demkin, Joseph A., editor
John Wiley & Sons, 2001
Buku Referensi
Hansen, Karen
John Wiley & Sons, 2011
Buku Teks
Hansen, Karen Lee
John Wiley & Sons, 2011
Buku Referensi
Edited by Cindy Coleman
McGraw-Hill, 2002
Buku Referensi