The preface mentions that writing biographies of saints yields spiritual fruit. Can you provide a list of the specific saints, besides Dnyaneshwar Maharaj, whose biographies are discussed?

The Preface (Chapter 0) of the Shri Sai Satcharita does not provide a list of specific saints whose biographies should be written. While it does mention that writing the biographies of saints is a form of Guru service that yields spiritual fruits, it focuses more on the principle itself rather than offering examples. The text's primary recommendation, as described in Chapter 0, is that the best and most certain service is to write the biography of one's own Sadguru, study it regularly, and encourage others to do so with unwavering devotion. The text cites Lord Samarth Sadguru Dnyaneshwar Maharaj not as an example for a biography, but for his teachings on serving a Guru.