TY  - RPRT
TI  - IGRFGRID : a program for creation of a total magnetic field (International Geomagnetic Reference Field) grid representing the earth's main magnetic field, Part A - Documentation
AU  - Ronald E. Sweeney
PY  - 1990
DO  - 10.3133/ofr9045a
UR  - https://pubs.usgs.gov/publication/ofr9045A
ID  - ofr9045A
ER  -