Northwest Airlines Schedule 1940 September 1
MLA
Northwest Airlines. "Northwest Airlines Schedule 1940 September 1." Delta Flight Museum. 1940-09-01, https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19400901.
APA
Northwest Airlines (1940-09-01). Northwest Airlines Schedule 1940 September 1. Retrieved from https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19400901
Chicago
Northwest Airlines. "Northwest Airlines Schedule 1940 September 1." 1940-09-01. October 6, 2026. https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19400901.
