Classification
YFA - Labour legislation
32
YBB - Law - general
14
YKP - German civil law
14
YDX - Contract law
11
YDA - Administrative law
9
TAA - Engineering sciences - reference books
8
YCA - Public law
7
YHA - Industrial property law, licensing rights
7
YNA - Patents, trademarks
7
CAA - Chemistry - reference books
6
YDM - Commercial law, commercial legislation
5
YDS - Building law
5
YFD - Public service legislation
5
YPB - Economy - general aspects
5
AAA - Encyclopedias - general aspects
4
ACE - Germanic languages, Indo-Germanic languages
4
YDG - Tax legislation
4
YDMB - Trade law
4
YEA - Environmental law
4
YEM - Energy law
4
YPG - Business management
4
ACA - Languages, dictionaries - general
3
YBA - Law - encyclopaedic glossaries
3
YEN - Atomic energy law
3
YZA - Politics, political science
3
ACH - Romance languages
2
HAA - Medicine - reference books
2
HYB - Public health, health politics
2
YDP - Foreign trade law, foreign currency law
2
YDY - Media, media law
2
YFH - Social legislation
2
YFK - Social insurance law
2
YPC - Public administration
2
YPM - National economy
2
AFA - Research institutions, scientific organizations - international and supranational
1
AHE - Research and development, research politics - foreign countries
1
HBA - Medical physics
1
HBC - Physiological chemistry, biochemistry
1
HPK - Special pharmacology, drug design
1
LAA - Biology - reference books
1
LTA - Biotechnology - reference books
1
LTU - Genetic engineering
1
TBA - Electronic engineering - general
1
TEA - Electrical engineering - general
1
TEJ - Electric devices, mechanical devices, magnets, dielectrics
1
TKA - Civil engineering - general
1
TNW - Nuclear controversy
1
UA - Environment - general
1
UKH - Environment and power plants, industrial plants
1
USG - Waste treatment, waste disposal
1
more ...