Guarnieri, M. (2012). "The age of vacuum tubes: Early devices and the rise of radio communications". IEEE Ind. Electron. M.: 41–43. doi:10.1109/MIE.2012.2182822. S2CID23351454.
Guarnieri, M. (2012). "The age of vacuum tubes: the conquest of analog communications". IEEE Ind. Electron. M.: 52–54. doi:10.1109/MIE.2012.2193274. S2CID42357863.
Guarnieri, M. (2012). "The age of vacuum tubes: Early devices and the rise of radio communications". IEEE Ind. Electron. M.: 41–43. doi:10.1109/MIE.2012.2182822. S2CID23351454.
Guarnieri, M. (2012). "The age of vacuum tubes: the conquest of analog communications". IEEE Ind. Electron. M.: 52–54. doi:10.1109/MIE.2012.2193274. S2CID42357863.