https://profiles.nlm.nih.gov/ps/retrieve/Narrative/BX/p-nid/350 Dennis, Clarence, Dwight S. Spreng Jr., George E. Nelson, Russell M. Nelson, John V. Thomas, Walter Phillip Eder, and Richard L. Varco ."Development of a Pump Oxygenator to Replace the Heart and Lungs: An Apparatus Applicable to Human Patients, and Application to One Case." Annals of Surgery, 134, no. 4 (October 1951): 709-721. نسخة محفوظة 2018-08-20 على موقع واي باك مشين.
https://profiles.nlm.nih.gov/ps/retrieve/Narrative/BX/p-nid/350 Dennis, Clarence, Dwight S. Spreng Jr., George E. Nelson, Russell M. Nelson, John V. Thomas, Walter Phillip Eder, and Richard L. Varco ."Development of a Pump Oxygenator to Replace the Heart and Lungs: An Apparatus Applicable to Human Patients, and Application to One Case." Annals of Surgery, 134, no. 4 (October 1951): 709-721. نسخة محفوظة 2018-08-20 على موقع واي باك مشين.