Helgason, Guðmundur. "WWI U-boat Types: Type UE 2". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U 117". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U 126". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U 118". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U 119". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U 120". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U 122". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U 123". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U-124". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "WWI U-boats: U-125". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "Ships hit by U 117". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "Ships hit by U 118". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
Helgason, Guðmundur. "Ships hit by Ships hit by U-122". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 24 January 2010.
web.archive.org
Goebel, Greg (24 December 2008). "The First Battle of the Atlantic". Vectorsite.net. Archived from the original on 10 March 2002. Retrieved 25 January 2010.