Not all these books are accurate. Many contain wild discrepancies in their understanding of the Nirvani Sanyasis and the Mahanirvani Peetam and it’s history. There are listed here only for people to understand the different views prevalent in the world.
A History of Dasnami Naga Sanyasis
Sir Jadunath Sarkar
P.A. Mahanirvani – Asceticism – 294 pages
Mathew Clark
KUMBH MELA
History and Religion; Astronomy and Cosmobiology
Ganga Cauvery Publishing House, Varanasi 1993 – 255 pages
Subhash Rai
Ganga Cauvery Publishing House, Varanasi 1993 – 255 pages
Subhash Rai
THE DASANAMI-SANYASIS 
The Integration of Ascetic Lineages into an Order
Brill Leiden, Boston 2006
Matthew Clark
Brill Leiden, Boston 2006
Matthew Clark
SADHUS IN CONTEMPORARY INDIA
Thesis, School of Social Sciences, JNU, 1999
Pushkar Mishra
Pushkar Mishra
WARRIOR ASCETICS
AND INDIAN EMPIRES
Cambridge University Press; Reprint edition (16 August 2012)
William R Pinch
William R Pinch
