Dolf Zillmann, Aaron Katcher, Barry Milavsky, "Excitation transfer from physical exercise to subsequent aggressive behavior," Journal of Experimental Social Psychology (1972), p. 247-259.

F.M. Christensen, Pornography The Other Side (1990), Praeger Publishers, p. 135-137.

Exercise enhancing any mood the subject is in:

Michael Turnbull and Sandy Wolfson, "Effects of Exercise and Outcome Feedback on Mood: Evidence for Misattribution", Journal of Sport Behavior Vol. 25, Issue 4 (December 2002).

see also:

Edward Donnerstein, Daniel Linz, and Steven Penrod, The Question of Pornography: Research Findings and Policy Implications (1987), The Free Press - A Division of MacMillan, Inc., Chap. 3, p. 41-42.

Marcia Pally, Sex & Sensibility (1994), Ecco Press, p. 42