Keen, A.W..
Frequency Modulation an Introduction to the Fundamental Principles / Keen A.W.. - London : Pitman and Sons, 1958. - XII, 274 s.: il.; 19 cm.
Frequency Modulation an Introduction to the Fundamental Principles / Keen A.W.. - London : Pitman and Sons, 1958. - XII, 274 s.: il.; 19 cm.