Gordon, M. S., Ewy, G. A., DeLeon, A. C., Waugh, R. A., Felner, J. M., Forker, A. D., … Patterson, D. (1980). "Harvey," the cardiology patient simulator: pilot studies on teaching effectiveness. Am J Cardiol, 45(4), 791–796. https://doi.org/10.1016/0002-9149(80)90123-x

Gordon, M. S., G. A. Ewy, A. C. DeLeon, R. A. Waugh, J. M. Felner, A. D. Forker, I. H. Gessner, J. W. Mayer, and D. Patterson. “"Harvey," the cardiology patient simulator: pilot studies on teaching effectiveness.” Am J Cardiol 45, no. 4 (April 1980): 791–96. https://doi.org/10.1016/0002-9149(80)90123-x.

Gordon MS, Ewy GA, DeLeon AC, Waugh RA, Felner JM, Forker AD, et al. "Harvey," the cardiology patient simulator: pilot studies on teaching effectiveness. Am J Cardiol. 1980 Apr;45(4):791–6.

Gordon, M. S., et al. “"Harvey," the cardiology patient simulator: pilot studies on teaching effectiveness.” Am J Cardiol, vol. 45, no. 4, Apr. 1980, pp. 791–96. Pubmed, doi:10.1016/0002-9149(80)90123-x.

Gordon MS, Ewy GA, DeLeon AC, Waugh RA, Felner JM, Forker AD, Gessner IH, Mayer JW, Patterson D. "Harvey," the cardiology patient simulator: pilot studies on teaching effectiveness. Am J Cardiol. 1980 Apr;45(4):791–796.