Gcod ʼdzin pa ran grol gyi ʼdon chaʼi skor : a system for the practice of Gcod from the revelations of Mdo Mkhyenbrtse Ye-śes-rdo-rje - Ye-śes-rdo-rje, Mdo Mkhyen-brtse, 1800-1859? (Ngodrub and Sherab Demy, 1978)