Melchionda, A. M., Clarkson, P. M., Denko, C., Freedson, P., Graves, J., & Katch, F. (1984). The effect of local isometric exercise on serum levels of beta-endorphin /beta-lipotropin. The physician and sportsmedicine, 12(9), S. 102-109. doi:10.1080/00913847.1984.11701948

Melchionda, Anthony M., Priscilla M. Clarkson, Charles Denko, Patty Freedson, James Graves, and Frank Katch. "The Effect of Local Isometric Exercise On Serum Levels of Beta-endorphin /beta-lipotropin." The Physician and Sportsmedicine 12, no. 9 (1984): S. 102-109.

Melchionda, Anthony M., et al. "The Effect of Local Isometric Exercise On Serum Levels of Beta-endorphin /beta-lipotropin." The Physician and Sportsmedicine 12.9 (1984): S. 102-109.