TY  - BOOK
AU  - Bartels,Julius
AU  - Romana,A.
AU  - Veldkamp,J.
TI  - Geomagnetic data 1957 indices K. and C. rapid variations
U1  - 538.74 
PY  - 1961///
CY  - Amsterdam
PB  - North Holland Publishing
KW  - Magnetic materials
KW  - Electric apparatus and appliances
N1  - Published with financial assistance from UNESCO
ER  -