Marathi is classified as an Indo-Aryan language (belonging to the southern branch of the Indo-Aryan language family along with Konkani). The following are the previous extensive surveys of variation in the Marathi language:

• Linguistic Survey of India, 1905. Vol. VII. George Grierson (Ed.). New Delhi: Motilal Banarsidass. Digital copies of the volume and gramophone recordings made during the survey may be found at https://dsal.uchicago.edu/books/lsi/.
• A Dialect Survey of Marathi. Amrit M. Ghatage (Ed.). The survey was conducted by the Deccan College, Pune. The survey findings were published by the Maharashtra State Board for Literature and Culture, Mumbai in the form of eight monographs published between 1963 and 1973. This partial survey of Marathi includes the following dialects: Kudali, Kunbi, Gawdi, Konkani of South Canara, Marati of Kasargod, Dialect of Cochin, and Konkani of Kankon. Digital copies of the monographs may be found at https://www.sahitya.marathi.gov.in.
• A Dialect Atlas of Marathi: A Pilot Study [Published in Marathi ‘Marathicha Bhashik Nakasha: Purvatayari]. Ramesh Dhongde (Ed.). Mumbai: Rajya Marathi Vikas Sanstha, 2013. This survey of lexical variation in Marathi was carried out at the Deccan College, Pune and was funded by the Rajya Marathi Vikas Sanstha, Mumbai. The survey was carried out in eight selected centres in Maharashtra and it included the elicitation of 2500 words across thirty-five semantic fields.
• People’s Linguistic Survey of India. [Published in Marathi ‘Maharashtrache Loksarvekshan’] Arun Jakhade (Ed.) Pune: Padmagandha Prakashan. 2013.

Publications of individual regional and social dialects of Marathi may be found in the journal Bhasha ani Jeewan.