Delta Air Lines System Timetable 1977 July 28
MLA
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1977 July 28." Delta Flight Museum. 1977-07-28, https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770728.
APA
Delta Air Lines, Inc. (1977-07-28). Delta Air Lines System Timetable 1977 July 28. Retrieved from https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770728
Chicago
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1977 July 28." 1977-07-28. May 7, 2026. https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770728.
