Smith, Sydney F.
Telephony and telegraphy : and introduction to instruments and switching systems (electromechanical and reed-electronic)
Oxford University Press, 1978
 Buku Teks
Briley, Bruce E.
Introduction to telephone switching
Addison-Wesley, 1983
 Buku Teks SO
Electronic switching : digital central office systems of the world
edited by Amos E. Joel, Jr.
IEEE Press : Sole Worldwide distributor, J. Wiley, 1982
 Buku Teks SO
Krause, Richard
Motor-uniselectors with noble-metal contacts in telephone switching systems
Van Nostrand Reinhold , 1970
 Buku Teks SO
Ali, Syed Riffat
Digital switching systems: system reliability and analysis
McGraw-Hill, 1997
 Buku Teks SO