Northwest Airlines Schedule 1940 May 1
MLA
Northwest Airlines. "Northwest Airlines Schedule 1940 May 1." Delta Flight Museum. 1940-05-01, https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19400501.
APA
Northwest Airlines (1940-05-01). Northwest Airlines Schedule 1940 May 1. Retrieved from https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19400501
Chicago
Northwest Airlines. "Northwest Airlines Schedule 1940 May 1." 1940-05-01. October 7, 2026. https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19400501.
