APA (7th ed.) Citation

Amundsen, R., Amundsen, R., Amundsen, R. E. G., & Ellsworth, L. (2023). Our polar flight. Project Gutenberg.

Chicago Style (17th ed.) Citation

Amundsen, Roald, Rual Amundsen, Roald Engelbregt Gravning Amundsen, and Lincoln Ellsworth. Our Polar Flight. Project Gutenberg, 2023.

MLA (9th ed.) Citation

Amundsen, Roald, et al. Our Polar Flight. Project Gutenberg, 2023.