Classification
UPN - Water protection, water quality, clean water
110
UPK - Water resources, water supply
106
UPT - Water pollution control and measurement
101
USN - Waste water treatment
100
UPCE - Water chemistry
76
URA - Soil chemistry
70
GTA - Hydrology - general
68
GNA - Geology - soil sciences
65
UPP - Water pollution
62
UPVC - Groundwater
54
UPC - Water - general aspects
50
TNE - Water cooled reactors
41
USNG - Waste water treatment - biological aspects
36
UCS - Environmental chemistry
35
UPW - Drinking water
34
GTAK - Hydrogeology
33
UPVF - Surface waters - streams, rivers, lakes
33
LWH - Agriculture - soil sciences
32
CHRV - Water and its properties
25
USK - Waste water
25
UAD - Environment - comprehensive works
23
UCA - Environmental problems, man and environment - general aspects
23
GMAB - Hydrogeochemistry
22
TNO - Nuclear reactor safety
22
UCQ - Environmental technology
22
UHN - Landscape ecology
22
UXS - Radioactive waste management
21
LCO - Hydrobiology
20
UPTF - Organic pollutants in water
20
USG - Waste treatment, waste disposal
20
USNH - Waste water treatment - special methods
20
UCE - Environmental impact, environmental pollution
19
EHA - Renewable energy sources
18
UCGE - Control of environmental pollution - analytical methods
18
UPA - Water - handbooks
17
EPK - Nuclear energy
16
GAN - Geosciences - mathematical methods, computer applications
15
GTAP - Hydrological investigation methods
15
UA - Environment - general
15
LCNC - Soil science - water transport
14
LCP - Limnology
14
LENI - Plant physiology - transport processes
14
UAN - Environment - mathematical methods, computer applications
14
EIK - Solar energy application
13
UAA - Environment - reference books
13
UHP - Protection of nature and landscape
13
CHTD - Chemistry of aqueous solutions
12
CWSW - Membrane separation process
12
GSC - Remote sensing
12
TNJ - Nuclear reactor technology
12
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