Could you provide details about the biographies authored by Shri Dasganu Maharaj as described in the source?

Certainly. Chapter 0 explains that Shri Dasganu Maharaj, a poet who was worthy of Shri Sai Baba's grace, wrote two biographies of Baba. The first is found in his work Bhaktalilamrut, specifically in Chapters 31, 32, and 33, consisting of 509 verses. The second is in Bhaktisaramrut, Chapters 52 and 53, containing 497 verses. Both are praised as excellent and heart-touching, but the text emphasizes that they are very short compared to the Shri Sai Satcharita, though they cover many of the same stories.