From Association to Public Library, 1883 to 1900: The Pre-History of Patchogue-Medford Library (Centennial Research Digest: PML History in Summary Form, Part I), by Mark Rothenberg (Patchogue-Medford Library. [Celia M. Hastings] Local History Room; PML Centennial Collection) - The section covering the years 1897 to 1900 details the involvement of Sorosis in the early years of the Library.
Patchogue Sorosis: The Early Years, 1897-1921 comp. by Mark Rothenberg. (Patchogue-Medford Library. Celia M. Hastings Local History Room) - The sections covering the years 1899, 1900 and 1911 detail more involvement of Sorosis in the early years of the Library.