Books:

Lane, Brian & Wilfred Gregg, The Encyclopedia of Mass Murder. Headline Book Publishing, 1994

Newton, Michael, Mass Murder. Garland. 1998

(July 1999). "Killer Left Notes Behind."

(November 1999). "No Motive in Hawaii."

Dart, Bob (Sept. 2000). "Study Calls 'Go Postal' Stereotype Mere Myth."    The AtlantaJournal-Constitution. 

Dube, Jonathan (2003). "Office Wars: Clients Attack Employees When They Feel Wronged." ABC News.

Hartman, Brian (July 1999). "Final Words: Atlanta Shooter Expresses Anger, Regret in Suicide Note." ABCNews.

Hartman, Brian (July 1999). "A Very Troubled Past.  ABCNews.

Injury Prevention Research Center (2001). Workplace Violence.

Kaufer, Steve and Mattman, Jurg (2001). Workplace Violence: An Employer's Guide.  Workplace Violence Research Institute.

Lee, George F. (1999). "7 Dead in Nimitz Hwy. Xerox Shooting."   Honolulu Star-Bulletin.

London, Sondra (1999)     Guns & Day Trading: Mark Barton.

Mashberg, Tom (2000). "Workplace violence called an epidemic". BostonHerald..

Massmurder.zyns.com

Newman, Cathy (Aug. 2000).  

"Going Postal?"

Sygnatur, Eric F & Toscano, Guy A. (2000). Work-related Homicides: The Facts. Compensation and Working Conditions.

The Associated Press (1999). "Barton Suspected in 1993 Murders." Associated Press.

The Occupational Safety and Health Administration (2002). OSHA Fact Sheet. U.S. Department of Labor.

Thompson, Dan (2001). "On The Edge: Managing High-Risk Situations."    Participant's Workbook. Edge Training Systems, Inc. HRD Press, Inc. MA, USA.

Violence Prevention Coalition of Greater Los Angeles (2003). "Violence in the Workplace."

White, Robert F. (1991). Workplace Violence: A Case Study. University of Maryland University College.