Bartels, J. <br/><br/>
Geomagnetic data indices K and C, 1961 
J. Bartels, A.Romana and J.  Veldkamp                                               
 - Amsterdam  North-Holland  1964 
 - 106p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geomagnetic data
<br/><br/><label>Universal Decimal Class. No.: </label>083.550.38  / IAGA-12P1