(1973). Telecommunications research in the United States and selected foreign countries: A preliminary survey. [Washington, D.C.]: National Academy of Engineering.
Παραπομπή Chicago StyleTelecommunications Research in the United States and Selected Foreign Countries: A Preliminary Survey. [Washington, D.C.]: National Academy of Engineering, 1973.
Παραπομπή MLATelecommunications Research in the United States and Selected Foreign Countries: A Preliminary Survey. [Washington, D.C.]: National Academy of Engineering, 1973.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.