Sorauf, Frank J.
Little, Brown, 1988
Buku Teks SO
Sorauf, Frank J.
Little, Brown, 1980
Buku Teks SO
Sorauf, Frank J.
Glenview, Ill. Scott Foresman and Co, 1988.,
Buku Teks
edited by Helen Jones and Susane Macgregor
Routledge, 1998
Buku Teks
Bone, Hugh A.
University of Washington Press, 1958
Buku Teks