Derived from File:Color etopo1 ice low.jpg, routes sourced by Rod Heikell, Andy O’Grady: Blauwasserrouten: Törnplanung - Wetterrouting - Landfall; Edition Maritim; Hamburg 2014; ISBN978-3-89225-711-0; Originalausgabe unter dem Titel Ocean Passages & Landfalls, Cruising routes of the world bei Imray.
The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use. [2]