Guillen, Tomas (2002). "Serial Killer Communiques: Helpful or Hurtful". Journal of Criminal Justice and Popular Culture. Fort Worth, Texas: Texas Wesleyan University. pp. 55–68. Archived from the original on 15 August 2017. Retrieved 10 April 2002.
Guillen, Tomas (2002). "Serial Killer Communiques: Helpful or Hurtful". Journal of Criminal Justice and Popular Culture. Fort Worth, Texas: Texas Wesleyan University. pp. 55–68. Archived from the original on 15 August 2017. Retrieved 10 April 2002.