James Check, The Effects of Violent and Nonviolent Pornography (1984, 1985), Department of Supply and Services Contract No. 05SV 1920 0-3-0899, Ottawa, Ontario: Canadian Dept. of Justice.
James Check and Ted Guloien, "Reported Proclivity for Coercive Sex Following Repeated Exposure to Sexually Violent Pornography, Nonviolent Dehumanizing Pornography, and Erotica", in Dolf Zillmann and Jennings Bryant (editors), Pornography: Research Advances and Policy Considerations (1989), Lawrence Erlbaum Associates.
Edward Donnerstein, Daniel Linz, Steven Penrod, The Question of Pornography: Research Findings and Policy Implications, (1987), The Free Press - A Division of MacMillan, Inc., p. 77-79.