1. Concertina Library: Digital Reference Collection for ...

    www.concertina.com

    Concertina Library: Documents for the study of English, Anglo, and Duet concertinas; history, instruction books, sheet music, patents, technical papers ...

  2. Concertina FAQ - www.concertina.info

    www.concertina.info

    Covers history, types, makes, repair and dealers.

  3. Charles Jeffries and His Sons: Concertina Makers – The ...

    https://www.concertinajournal.org/.../charles-jeffries-and-his-sons

    Chris Algar, Stephen Chambers, Robert Gaskins, David Lee, Randall C. Merris, and Wes Williams. This Charles Jeffries never knew a thing, never been taught anything—