Here is an article on the reference to Rudra and Āditya in the Bhagavadgītā bhāṣyam 6.47 by Shankaracharya: http://www.mediafire.com/download/610a95362eprvy3/Reference+to+Rudra+and+%C4%80ditya+in+the+Bh.g.pdf subrahmanian.v