Roskill 1957, p. 479; Hobbs 2013, p. 198. Roskill, S. W. (1957) [1954]. Butler, J. R. M. (ed.). The Defensive. History of the Second World War United Kingdom Military Series: The War at Sea 1939–1945. Vol. I (4th impr. ed.). London: HMSO. OCLC881709135. Retrieved 21 December 2015. Hobbs, David (2013). British Aircraft Carriers: Design, Development and Service Histories. Barnsley: Seaforth (Pen & Sword Books). ISBN978-1-84832-138-0.
Roskill 1957, p. 479; Hobbs 2013, p. 198. Roskill, S. W. (1957) [1954]. Butler, J. R. M. (ed.). The Defensive. History of the Second World War United Kingdom Military Series: The War at Sea 1939–1945. Vol. I (4th impr. ed.). London: HMSO. OCLC881709135. Retrieved 21 December 2015. Hobbs, David (2013). British Aircraft Carriers: Design, Development and Service Histories. Barnsley: Seaforth (Pen & Sword Books). ISBN978-1-84832-138-0.