Parkinson, John and D. Evan Bedford. "The pulmonary artery impression on the a esophagus." Reprinted from Lancet, 15 August 1931.

Parkinson, John and D. Evan Bedford. "The pulmonary artery impression on the a esophagus." Reprinted from Lancet, 15 August 1931., Box: 4. Veterinary Reprint and Pamphlet Collection, 24-4-3369. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/263107 Accessed December 20, 2025.