Uttara Gita is a famous text containing the conversation of Lord Kesava with Arjuna.
Traditional scholars claim that the Uttara-Gita has taken as its source the Asvamedha Parva of the Mahabharata. However, in one chapter of the Bhisma Parva there is a section of approximately fifty slokas that is popularly known as the Gitasara. Much of this section bears a marked resemblance to the text of the Uttara-Gita.
The english translation of this work is available from many sources.
Gaudapada Acharya has written a commentary for this text. The sanskrit text of the commentary is available but is an English translation available? Portions of the english translation of this commentary are available but I am asking for the complete English translation.
Shankara has cited this work of his paramaguru in his bhashyas. For example, in bhagavad gita bhashya 13.13, he cites 1.7 of the bhashya. Swami Vidyaranya extensively cites this work in his Taittiriya Upaniṣad Dipika.