Classification
YPG - Business management
69
YDX - Contract law
32
EKA - Wind energy
27
YPB - Economy - general aspects
26
YDA - Administrative law
24
YCA - Public law
23
EHA - Renewable energy sources
22
YDE - Financial law, budgetary law
22
YFA - Labour legislation
21
AZZ - Firm index - general
18
ACE - Germanic languages, Indo-Germanic languages
16
AHF - Research and science
16
ACA - Languages, dictionaries - general
15
LTA - Biotechnology - reference books
15
EXA - Energy policy
13
EUR - District heating
12
YBB - Law - general
12
YPGE - Human resource planning, human resource management
12
AHC - Research and development, research politics - Germany
11
AMA - Education - general
10
DTAE - MS - Access
10
ENA - Energy from biomass and waste
10
LTE - Biotechnology - general aspects
10
YFD - Public service legislation
10
DMF - Software engineering
9
TKB - Civil engineering - buildings
9
YPD - Business economics
9
YPH - Secretarial work, office management
9
AHA - Research and development, research politics - general
8
YKP - German civil law
8
YMA - International law
8
LAA - Biology - reference books
7
LHL - Microbiology - general aspects
7
UEF - Sustainability
7
YPGN - Project management
7
YRB - Social sciences, sociology
7
YRC - Technology and society
7
AES - Universities, academies - Germany
6
AHN - Media and communication science
6
CAA - Chemistry - reference books
6
DOQ - Programming languages - Internet
6
DUA - Text and document processing
6
EIP - Photovoltaics
6
EWA - Energy economy
6
FAO - Materials science - introductions
6
LKA - Biochemistry - reference books
6
LTN - Biotechnology - biodegradation
6
YDM - Commercial law, commercial legislation
6
YHA - Industrial property law, licensing rights
6
YNA - Patents, trademarks
6
more ...