Columbia subject headings:
Gravity anomalies--Maps--Research.
Gravity anomalies.
Magnetic anomalies--Maps--Research.
Magnetic anomalies.
Harvard subject headings:
Gravity anomalies--Canada--Maps.
Gravity anomalies--Congresses.
Gravity anomalies--United States--Maps.
Magnetic anomalies--Canada--Maps.
Magnetic anomalies--Congresses.
Magnetic anomalies--United States--Maps.
Princeton subject headings:
Gravity anomalies--Maps--Research.
Gravity anomalies.
Magnetic anomalies--Maps--Research.
Magnetic anomalies.