Caravelas Class Rio Tocantins class Barracuda(Marlin級) Patrol River LPR-40 Poraque Anhatomirim(Aratù級) Almirante Gastão Motta Mearin class Triunfo(Triunfo級)
Patrol info for U-31 (4th patrol). German U-boats of WWII - uboat.net. [2024-03-20]. (原始内容存档于2022-07-06). Helgason, Guðmundur. Patrol info for U-31 (5th
Guðmundur. Patrol info for U-26 (Fourth patrol). German U-boats of WWII - uboat.net. [2023-08-02]. Helgason, Guðmundur. Patrol info for U-26 (Fifth patrol). German