Corrigan, Timothy
Scott, Foresman and Company, 1989
Buku Teks
Pechenik, Jan A.
Longman , 2001
Buku Teks
Pechenik, Jan A.
Pearson Longman, 2007
Buku Teks
Dunn, Dana S.
Longman, 2011
Buku Teks
Barnet, Sylvan
Batsford Academic and Educational, 1985
Buku Teks