How can devotees serve their Sadguru through literature and books?

According to Chapter 0, a Sadguru accepts two primary forms of service from devotees through books. The first is when the Guru themselves creates a great work, like Shri Dnyaneshwari. The second, more common for devotees, is when the Guru has their biographies written by their followers. Devotees can then perform service through the dedicated study and Parayans (devotional readings) of these biographies. This act of service extends not just to the writer but also to the entire congregation of devotees who participate, allowing them to achieve the purpose of their lives.