Gabriel, H. H. W., Urhausen, A., Valet, G., Heidelbach, U., & Kindermann, W. (1998). Overtraining and immune system: A prospective longitudinal study in endurance athletes. Medicine and science in sports and exercise, 30(7), S. 1151-1157.

Gabriel, Holger Horst Werner, A. Urhausen, G. Valet, U. Heidelbach, and W. Kindermann. "Overtraining and Immune System: A Prospective Longitudinal Study in Endurance Athletes." Medicine and Science in Sports and Exercise 30, no. 7 (1998): S. 1151-1157.

Gabriel, Holger Horst Werner, et al. "Overtraining and Immune System: A Prospective Longitudinal Study in Endurance Athletes." Medicine and Science in Sports and Exercise 30.7 (1998): S. 1151-1157.