Badawy, M., A. Mohamed, A. Maher, and R. Tarazi. “Heparin Versus No Heparin before Endoscopic Vein Harvesting Using Angioscopy”. The Egyptian Cardiothoracic Surgeon, Vol. 3, no. 6, Nov. 2021, pp. 139 -43, doi:10.35810/ects.v3i6.197.