M.N. Avadhanulu et P.G. Kshirsagar, A Textbook Of Engineering Physics For B.E., B.Sc., S. Chand, , 345–348 p. (ISBN8121908175, lire en ligne)
Ferris, Clifford "Electron tube fundamentals" in Jerry C. Whitaker, The Electronics Handbook, 2nd Ed., CRC Press, , 354–356 p. (ISBN1420036661, lire en ligne)