Adams, Henry
Houghton Miffiln, 1918
Buku Teks
Decker, William Merrill
University of North Carolina Press, 1990
Buku Teks
Swan, Michael, author
Longmans, 1950
Buku Teks
Swan, Michael, author
Longmans Green, 1969
Buku Teks
Kramer, Leonie, author
Sun Books, 1973
Buku Teks