Berko, Roy M, author
Houghton Miffiln, 2001
Buku Teks
Hamilton, Cheryl, author
Thomson/Wadsworth, 2011
Buku Teks
Hamilton, Cheryl
Wods Worth Publishing, 1993
Buku Teks
De Mare, George
John Wiley , 1979
Buku Teks
Hamilton, Cheryl
Wadsworth, 1982
Buku Teks