538.7 Car D Carnegie Institution of Washington Description of the earth´s main magnetic field and its secular change, 1905-1945 [by] E.H. Vestine [and others] Washington, 1947 v, 532 p. ilus. 28 cm. (Carnegie Institution of Washington. Publñication 578) ´´Literature cited´´: p. 532<a id= "rdfa" about="http://bnjm.sld.cu/cgi-bin/item.py?idficha=bcuhcgrlyfof0170420" property = "oa:link" href="http://www.worldcat.org/oclc/ 977063176 ">WorldCat</a>