Detry, JMR., Decoster, PM., & Renkin, J. (1983). Hemodynamic-effects of Felodipine At Rest and During Exercise in Exertional Angina-pectoris. The American Journal of Cardiology, 52(5), 453-457. https://doi.org/10.1016/0002-9149(83)90006-1 (Original work published 1983)