00594nam a22001937a 4500 BD-DhUL 20150115174658.0 150115s1949 -usa|||| |||| 001 0 eng d BD-DhUL BD-DhUL DEI 621.384 U. S. Department of Commerce. Iouspheric radio propagation / U. S. Department of Commerce. Washington : National Bureau of Standards , 1949. iv, 209 p. : ills. ; 25 cm. National Bureau of Standards Circular 462. Includes index. Radio ddc BK 31877 31877 0 0 ddc 0 621_384000000000000_DEI 0 NFIC 60037 DUSL DUSL GEN 2015-01-15 purchased 621.384 DEI 56161 2015-01-15 2015-01-15 BK