Delta Air Lines System Timetable 1940 July 25
MLA
Delta Air Corporation. "Delta Air Lines System Timetable 1940 July 25." Delta Flight Museum. 1940-07-25, https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19400725.
APA
Delta Air Corporation (1940-07-25). Delta Air Lines System Timetable 1940 July 25. Retrieved from https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19400725
Chicago
Delta Air Corporation. "Delta Air Lines System Timetable 1940 July 25." 1940-07-25. May 12, 2026. https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19400725.
