In what ways does a Sadguru accept service from devotees through the medium of books?

Chapter 0 outlines two primary ways a Sadguru takes service from his devotees through books. The first method is when the Guru creates great works himself, such as the Shri Dnyaneshwari or Shri Dasbodh. The second method, which is highly relevant for building a community, is when the Sadguru has his biographies written by his devotees. The Guru then accepts service in the form of study and Parayans of these biographies from both the writer and the entire congregation of devotees, creating a shared spiritual practice that unifies the followers.