Northwest Airlines Schedule 1939 June 15
MLA
Northwest Airlines. "Northwest Airlines Schedule 1939 June 15." Delta Flight Museum. 1939-06-15, https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19390615.
APA
Northwest Airlines (1939-06-15). Northwest Airlines Schedule 1939 June 15. Retrieved from https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19390615
Chicago
Northwest Airlines. "Northwest Airlines Schedule 1939 June 15." 1939-06-15. October 11, 2026. https://dlg.galileo.usg.edu/do:delta_nwa-tt_nwa-tt-19390615.
