1. Police report from 29th October 1936, The National Archives, Home Office (TNA HO) 144/21062.
2. Police report from 12th March 1937, TNA HO 144/21063.
3. Police report from 18th February 1938, TNA HO 144/21281.
4. Police report from 28th February 1939a, TNA HO 144/21281.
5. Police report from 28th February 1939b,(Excerpts from the Monthly Letter No. 20), TNA HO 144/21281.