Delta Air Lines System Timetable 1977 April 24
MLA
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1977 April 24." Delta Flight Museum. 1977-04-24, https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770424.
APA
Delta Air Lines, Inc. (1977-04-24). Delta Air Lines System Timetable 1977 April 24. Retrieved from https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770424
Chicago
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1977 April 24." 1977-04-24. July 16, 2025. https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19770424.
