Fowler, J. H., Dutton, C. B., Killeen, R. R., Irish Self-Determination League of Great Britain, & Great Britain. Post Office. (1923). Circulars issued by Irish Self-Determination League Emergency (Executive) Committee to all branch secretaries following arrest of Art Ó Briain and Seán McGrath, with typescript copy letters of Ó Briain and letter from General Post Office, London, to Winifride Gillespie regarding missing postal orders for ISDL.

Fowler, Joseph H., et al. Circulars Issued by Irish Self-Determination League Emergency (Executive) Committee to All Branch Secretaries Following Arrest of Art Ó Briain and Seán McGrath, with Typescript Copy Letters of Ó Briain and Letter from General Post Office, London, to Winifride Gillespie Regarding Missing Postal Orders for ISDL. 1923.