Roskill 1962, p. 287; Hutson 2012, pp. 126–127. Roskill, S. W. (1962) [1956]. Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Period of Balance. History of the Second World War, United Kingdom Military Series. Vol. II (3rd ed.). London: HMSO. OCLC174453986. Retrieved 19 March 2018. Hutson, H. C. (2012). Arctic Interlude: Independent to North Russia (6th ed.). CreateSpace Independent Publishing. ISBN978-1-4810-0668-2.
Schofield & Nesbit 2005, pp. 168–171; Roskill 1962, pp. 282–283. Schofield, Ernest; Nesbit, Roy Conyers (2005). Arctic Airmen: The RAF in Spitsbergen and North Russia 1942 (2nd ed.). London: W. Kimber. ISBN978-1-86227-291-0. Roskill, S. W. (1962) [1956]. Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Period of Balance. History of the Second World War, United Kingdom Military Series. Vol. II (3rd ed.). London: HMSO. OCLC174453986. Retrieved 19 March 2018.
Roskill 1962, p. 287; Hutson 2012, pp. 126–127. Roskill, S. W. (1962) [1956]. Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Period of Balance. History of the Second World War, United Kingdom Military Series. Vol. II (3rd ed.). London: HMSO. OCLC174453986. Retrieved 19 March 2018. Hutson, H. C. (2012). Arctic Interlude: Independent to North Russia (6th ed.). CreateSpace Independent Publishing. ISBN978-1-4810-0668-2.
Roskill 1960, p. 59. Roskill, S. W. (1960). Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Offensive, Part I: 1st June 1943 – 31st May 1944. History of the Second World War, United Kingdom Military Series. Vol. III. London: HMSO. OCLC570500225.
Roskill 1960, pp. 59, 63. Roskill, S. W. (1960). Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Offensive, Part I: 1st June 1943 – 31st May 1944. History of the Second World War, United Kingdom Military Series. Vol. III. London: HMSO. OCLC570500225.
Schofield & Nesbit 2005, pp. 168–171; Roskill 1962, pp. 282–283. Schofield, Ernest; Nesbit, Roy Conyers (2005). Arctic Airmen: The RAF in Spitsbergen and North Russia 1942 (2nd ed.). London: W. Kimber. ISBN978-1-86227-291-0. Roskill, S. W. (1962) [1956]. Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Period of Balance. History of the Second World War, United Kingdom Military Series. Vol. II (3rd ed.). London: HMSO. OCLC174453986. Retrieved 19 March 2018.