(1978). Laser beam information systems. New York: Petrocelli Books.
Dyfyniad Arddull ChicagoLaser Beam Information Systems. New York: Petrocelli Books, 1978.
Dyfyniad MLALaser Beam Information Systems. New York: Petrocelli Books, 1978.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.