TY  - RPRT
TI  - Spectral characteristics of geomagnetic field variations at low and equatorial latitudes
AU  - W.H. Campbell
PY  - 1977
DO  - 10.1016/0021-9169(77)90031-9
UR  - https://pubs.usgs.gov/publication/70010407
ID  - 70010407
ER  -