In the early decades of the 20th century, Benoytosh Bhattacharya – an expert on Tantra and the then director of the Oriental Institute of Baroda – studied various texts such as the Buddhist "Sadhanamala" (1156CE), the Hindu "Chhinnamastakalpa" (uncertain date), and the "Tantrasara" by Krishnananda Agamavagisha (late 16th century). He determined that the Hindu Chhinnamasta and the Buddhist Chinnamunda were the same goddess, in spite of the fact that the former wears a serpent as a sacred thread and has an added copulating couple in the icon. In the "Sadhanamala", the goddess is called Sarvabuddha ("all-awakened"), and is attended by Vajravaironi and Vajravarnini; in the Hindu "Tantrasara", she is called "Sarvasiddhi" ("all-accomplished"), and is accompanied by attendants Dakini, Vaironi, and Varnini. In the "Chhinnamastakalpa", she is called Sarvabuddhi ("all-enlightened"); her attendants retain their Buddhist names. Bhattacharyya concluded that the Hindu Chhinnamasta originated from the Buddhist Chinnamunda, who was worshipped by at least the 7th century.