Related to the Sylhet Referendum of 1947, it is one of the six referendums in India history that changed the face of our country. I have made a list of the most popular and quoted articles/books
1.You can visit www.jstor.org, register and get free online access to the article The Sylhet Referendum (1947): Myth of a Communal Voting by JB Bhattacharjee,Vol. 51 (1990), pp. 482-487.
2. Although not a book, for credible information, you can also contact the 'IHC' Indian History Congress, which has members and experts in subjects from ancient-Modern India
Room No.33 ,Department of History
Mobile No: 08791455786/09760666637
3.A'God-sent opportunity' Sujit Chaudhuri related to Sylhet referendum and Assam's loss of a district.(http://www.india-seminar.com/2002/510/510%20sujit%20chaudhuri.htm)
4.The 'hut' and the 'axe': The 1947 Sylhet referendum by Bidyut Chakrabarthy, The Indian Economic and Social History review, Volume: 39 issue: 4, page(s): 317-350
Issue published: December 1, 2002
the free abstract is in this link, it needs a payment for the full article.
5.History and Politics of Partition:
Assam and Sylhet. This is a 41 page pdf file that you can download for free. This has maps, census data, impact of the referendum and 8 key points with names and references.
6.Politics of Subversion:The Untold Story of Sylhet by Sujith K Ghosh. Book that can be bought from Amazon or for a reference library close to you.
7.Remembering Sylhet: Hindu and Muslim Voices from a Nearly Forgotten Story of India's Partition by Anindita Dasgupta.Book that can be bought from Amazon or for a reference library close to you.
7.Introducing Sylhet: historical outline, research concerns, and others, 43 page downloadable pdf file. This has maps and 10 important notes point with key events and the time line
8. Remembering Sylhet: A. Dasgupta, this free pdf article has 13 references in the last page 5.https://bangalnama.files.wordpress.com/2009/07/remembering-sylhet-a-dasgupta.pdf