Delta Air Lines System Timetable 1971 August 1
MLA
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1971 August 1." Delta Flight Museum. 1971-08-01, https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19710801.
APA
Delta Air Lines, Inc. (1971-08-01). Delta Air Lines System Timetable 1971 August 1. Retrieved from https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19710801
Chicago
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1971 August 1." 1971-08-01. August 8, 2025. https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19710801.