edited, Charles E. Orser
Routledge, 2002
Buku Referensi
South, Stanley
Academic Press, 1977
Buku Teks SO
McDowell, W. H.
Longman, 2002
Buku Teks SO
Edited by Don Brothwell, Eric Higgs
Thames and Hudson, 1971
Buku Referensi
Rubin, Rebecca B.
Wadsworth, 1993
Buku Teks SO