Eulau, Heinz, author
Bobbs-Merrill, 1963
Buku Teks
Dyke, Vernon van, author
Nelson, 1992
Buku Teks
Merriam, Charles E. (Charles Edward), author
University of Chicago Press, 1957
Buku Teks
Jesss Ballesteros
Springer, 2012
eBooks
edited by Stephen White, Judy Batt and Paul G. Lewiss
Macmillan, 1993
Buku Teks