Johnson, Richard E., author
Houghton Mifflin , 1972
Buku Teks
Dillingham, Alan E.
Allyn and Bacon , 1992
Buku Teks
Andrew Mcclelan
Blackwell Publishing, 2006
Buku Teks
Huish, Marcus B.
B.T. Batsford, 1912
Buku Teks
Bovini, Giuseppe
Fratelli Lega Editori,
Buku Teks