00266nam a2200109Ia 450000500170000000800410001708200140005810000140007224500290008626000330011530000080014820260224040845.0260224s9999||||xx |||||||||||||| ||und||  a621.3 KEM  aKemp, P.  0aElectrical engineering    aLondon: Pitman & Sons,c1950  a637