Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The term "Sadhukkari" was coined by Ramchandra Shukla (1884-1941), and not all scholars agree with the use of this term, or the identity of the languages which it covers.
^ Amiya Dev; Sisir Kumar Das (1989). Comparative literature: theory and practice. Indian Institute of Advanced Study in association with Allied Publishers. p. 110. ISBN8170230179.
Sushama Merh-Ashraf (2004). Adult education in India: search for a paradigm. Sunrise Publications. p. 186. ISBN8187365129.
Robert W. Stevenson (1994). Hermeneutical paths to the sacred worlds of India: essays in honour of Robert W. Stevenson. Scholars Press. p. 232. ISBN1555409520.