edited by Frank N. Kemmer
McGraw-Hill, 2009
Buku Referensi
Mays, Larry W.
McGraw-Hill, 2000
Buku Referensi
Larry W. Mays
McGraw-Hill, 2002.
Buku Teks
Alley, E. Roberts
Mcgraw-Hill, 2000
Buku Referensi
compiled by Michael and Irene Ash
Gower, 1996
Buku Referensi