Delta Air Lines System Timetable 1981 March 1
MLA
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1981 March 1." Delta Flight Museum. 1981-03-01, https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19810301.
APA
Delta Air Lines, Inc. (1981-03-01). Delta Air Lines System Timetable 1981 March 1. Retrieved from https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19810301
Chicago
Delta Air Lines, Inc.. "Delta Air Lines System Timetable 1981 March 1." 1981-03-01. May 17, 2026. https://dlg.galileo.usg.edu/do:delta_dal-tt_dal-tt-19810301.
