Topic
& Business Aspects
5
& Exploration
7
& Processing
1
& Utilization-- Industrial & Agricultural Processes
1
& Utilization-- Industrial & Agricultural Processes-- Equipment & Processes
1
01 Coal
2
02 Petroleum
52
020300 -- Petroleum-- Drilling & Production
1
020700 -- Petroleum-- Economics
4
020900
1
020900 -- Petroleum-- Environmental Aspects
2
03 - Natural Gas Economic Profitability
1
03 Natural Gas
43
030200
1
030200 -- Natural Gas-- Reserves
1
030600
1
08 Hydrogen
1
11 Nuclear Fuel Cycle And Fuel Materials
1
15 Geothermal Energy
1
29 Energy Planning
3
290400 -- Energy Planning & Policy-- Energy Resources
1
294002 -- Energy Planning & Policy-- Petroleum
2
30 Direct Energy Conversion
1
32 Energy Conservation
2
320300 -- Energy Conservation
1
33 Advanced Propulsion Systems
3
36 Materials Science
1
42 Engineering Millimeter Wave Radiometry
1
47 Other Instrumentation
1
54
1
54 Environmental Sciences
52
54 Environmental Sciences Cloud Microphysics
1
54 Environmental Sciences Clouds
1
540110
1
540250
1
540250 -- Environment
1
540310
1
540330
1
56 Biology And Medicine
1
58
1
58 Geosciences
9
580000
1
580000 -- Geosciences
2
99 General And Miscellaneous//Mathematics
2
ALASKA NORTH SLOPE
3
ANWR
1
ATTENUATION
1
Ablation
2
Absorption
1
Abundance
1
more ...