Helgason, Guðmundur. "WWI U-boat commanders: Otto Rohrbeck". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 20 January 2015.
Helgason, Guðmundur. "WWI U-boat commanders: Karl Thouret". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 20 January 2015.
Helgason, Guðmundur. "WWI U-boat commanders: Martin Hoffmann". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 20 January 2015.
Helgason, Guðmundur. "WWI U-boat commanders: Woldemar Petri". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 20 January 2015.
Helgason, Guðmundur. "WWI U-boat commanders: Kurt Slevogt". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 20 January 2015.
Helgason, Guðmundur. "Ships hit by U 79". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 20 January 2015.