edited by Ralph Cohen
Sheridan Press, 1989
Buku Referensi
Ryan, Michael, 1951-
Wiley-Blackwell, 2017
Buku Teks SO
edited by Julie Rivkin and Michael Ryan
John Wiley & Sons, 2017
Buku Teks SO
Duke University Press, 1995
Buku Teks
Klarer, Mario, 1962-
Routledge, 2005
Buku Teks