538.7083
Car
E
 Carnegie Institution of Washington. Dept. of Terrestrial Magnetism. 
   Earth-current results at Tucson Magnetic Observatory, 1932-1942 [by] W.J. Rooney. Washington, 1949
    v, 309 p.  tablas.  28 cm. (Carnegie Institution of Washington. Publication 175)

   A la cabeza del títulos: ´´Researches of the Departament of Terrestrial Magnetism, vol. 9´´