Psr777, you might want to try and track down some of the following articles:-
1. Caldwell, J.A. (1997) Fatigue in the Aviation Environment: An Overview of the Causes and Effects As Well As Recommended Countermeasures, Aviat Space and Environ Med 1997, 68:932-8.
2. NTSB (1994). Safety Study: A Review of Flight Crew Involved, Major Accidents of U.S. Air Carriers, 1978-1990. PB94-917001 NTSB/SS-9401. Washington, D.C: NTSB.
3. Battelle Memorial Institute. (1998) A Review of Issues Concerning Duty Period Limitations, Flight Time Limitations, and Rest Requirements. Federal Aviation Administration (AAR-100). Washington, D.C.
4. Colquhoun, P. (1976). Psychological and Psychophysiological Aspects of Work and Fatigue. Activitas Nervosa Superior, 18, 257-263.
5. Dinges, D.F. (1995) Performance Effects of Fatigue. Fatigue Symposium Proceedings. Washington, D.C: NTSB
M.