Cohen, Morris L.
West Publishing, 1989
Buku Teks SO
Cohen, Morris L.
West Publishing, 1983
Buku Teks SO
Mann, Thomas
Oxford University Press, 2005
Buku Teks SO
Clinch, Peter
Aslib-IMI, 2000
Buku Teks SO
edited ny Jeffrey T. Huber
Haworth Press, 1992
Buku Referensi