My Guru is not mentioned anywhere in this text. Does that mean their teachings are less valuable or that the book is incomplete?

The text does not claim to be an exhaustive list of all gurus. Instead, as Chapter 19 explains, our connections are often due to "the ties of past debts (Rinanubandha), we have met by good fortune." Your connection to your Guru is unique. The book focuses on the author's experience, emphasizing principles that can be applied universally. It states, "the words 'Ye yatha mam' (As they approach me...) put the entire burden on one's actions." Therefore, the value comes from your own actions and devotion, not from whether a specific name is mentioned in this particular text.