1. More chest roentgen signs and how to teach them;Felson;Radiology,1968
2. Principles of Chest Roentgenology, A Programmed Text;Felson,1965
3. Case of the Week;Felson,1967
4. Fleischner, F. G.: Personal communication.
5. Freimanis, A. K.: Teaching radiology to medical students and interns. Course No. 600, 54th Scientific Assembly and Annual Meeting, The Radiological Society of North America, Inc., December, 1968.