http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
5 maps : color ; 63 x 100 cm., on sheets 86 x 122 cm.
D. Declination chart -- F. Total intensity chart -- H. Horizontal intensity chart -- I. Inclination chart -- Z. Vertical intensity chart.
U.S. Department of the Interior, U.S. Geological Survey ; by Norman W. Peddie.
"Five world charts showing ... earth's magnetic field at mean sea level at the beginning of 1990."
Includes 2 ancillary maps of the polar regions. Scale 1:60,192,000 (along meridians only).
Scale 1:40,053,700 (along equator only) ;
Geophysical investigations (Geological Survey (U.S.)) ; GP-1004