Delta Air Lines System Timetable 1977 September 15
MLA
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1977 September 15." Delta Flight Museum. 1977-09-15, https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770915.
APA
Delta Air Lines, Inc. (1977-09-15). Delta Air Lines System Timetable 1977 September 15. Retrieved from https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770915
Chicago
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1977 September 15." 1977-09-15. July 1, 2025. https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770915.
