TY  - RPRT
TI  - Evaluation of the 1985-1990 IGRF secular variation candidates
AU  - J.C. Cain
AU  - C. Kluth
PY  - 1987
DO  - 10.1016/0031-9201(87)90161-0
UR  - https://pubs.usgs.gov/publication/70014180
ID  - 70014180
ER  -