Harman, Harry H.
University of Chicago Press, 1968
Buku Teks SO
Hummel, James A.
Addison-Wesley , 1967
Buku Teks SO
Hoskins, R.F.
Ellis Horwood, 1979
Buku Teks SO
Zink, Harold
D. Van Nostrand, 1962
Buku Teks
edited by Allen Cunningham; preface by Robert Maxwell
Routledge, 1998
Buku Teks SO