Garda Siochana Retired Members Association
Royal Ulster Constabulary George Cross Foundation
Garda Siochana Historical Society
Garda Historical Society – Facebook page
Royal Irish Constabulary, 1816-1922 – A forgotten force – Facebook group
Police Service of Northern Ireland Museum
The Dublin Metropolitan Police (DMP) Prisoners Books for 1905-1908 and 1911-1918
The Dublin Metropolitan Police – General Register of Service, 1836-1925
The Civic Guard (Garda Siochana) Temporary Register, 1922-1929