Subject
Texas
5
Geology
2
Alaska
1
Chemistry, Inorganic
1
Coal
1
Cuba
1
Geology, Economic
1
Indian Territory Boundaries
1
Iron ores Analysis
1
Mineralogy
1
Natural gas
1
New Mexico Boundaries
1
Paleobotany
1
Paleontology
1
Petroleum
1
Petrology
1
Platinum
1
Texas Boundaries
1
Texas Description and travel
1
United States Altutides
1
United States Boundaries
1
Utah
1
Water-supply
1