1. ARNETT , H. D. , 1962 , U. S. Naval Research Laboratory 5749 , Report March 16 .
2. Electron beam coupling in interaction gaps of cylindrical symmetry
3. Plasma frequency reduction factors in electron beams
4. DERFLER , H. , 1961 , QSR No. 18 , Electron Devices Laboratory, Stanford Electronics Laboratories , Stanford , California , April-June .