TY  - RPRT
TI  - An attempt to obtain a detailed declination chart from the United States magnetic anomaly map
AU  - L.R. Alldredge
PY  - 1989
DO  - 10.5636/jgg.41.549
UR  - https://pubs.usgs.gov/publication/70015493
ID  - 70015493
ER  -