GARBE
According to Garbe, the Bhagwat Gita was earlier a scripture related to Sankhyayoga, in which the procedure of the worship of Krishna Vasudeva was added later on and in the third century B.C. it was mixed with the Vedic tradition by considering Krishna to be a form of Vishnu. The original composition was written 200 B.C. and its modern form was prepared by a follower of Vedanta in second century A.D.