Subject
Tax auditing
44
Longwall mining
23
Coal mines and mining
15
Geology
15
Mine roof control
15
Intelligent transportation systems
13
Nutrition surveys
13
Natural gas pipelines Environmental aspects
12
Water resources development
12
Mines and mineral resources
11
Traffic accidents
10
Ground control (Mining)
9
History
9
Leaching
9
Mine dusts
9
Mine ventilation
9
Rock mechanics
9
Traffic safety
9
Boring
8
Coal mines and mining Dust control
8
Coal mines and mining Safety measures
8
Fire prevention Research
8
Industrial hygiene
8
Industrial safety
8
Management
8
Radioactive waste disposal
8
Reclamation of land
8
Tax administration and procedure
8
Water quality
8
Children Nutrition
7
Geomagnetism
7
Groundwater Pollution
7
Hydroelectric power plants Environmental aspects
7
Water-supply
7
Women Nutrition
7
Air Pollution
6
Air traffic control
6
Coal Geology
6
Computer-aided design
6
Hydrology
6
Mine subsidences
6
Officials and employees
6
Transportation and state
6
Coalbed methane
5
Customs administration
5
Emergency medical services Study and teaching
5
Environmental monitoring
5
Federal aid to transportation
5
Food consumption
5
Groundwater Purification
5
more ...