Classification
ACE - Germanic languages, Indo-Germanic languages
10
ACA - Languages, dictionaries - general
6
ACH - Romance languages
3
AHL - Presentations, lectures, discussions
3
AHK - Scientific work
2
AHNC - Journalism
2
AXM - Guidebooks - Cities
2
LCO - Hydrobiology
2
YPGL - Public relations
2
AFG - Large scale research institutions (Helmholtz Centres)
1
AFS - Foundations, prizes
1
AHC - Research and development, research politics - Germany
1
AHE - Research and development, research politics - foreign countries
1
AHF - Research and science
1
AHH - Universities - research
1
AHN - Media and communication science
1
AHZ - History of science and technology
1
AJA - Directories - general
1
AXA - Geographic surveys - specific countries
1
DTAI - MS - Office package - diverse
1
DUA - Text and document processing
1
EIM - Solar architecture
1
EPK - Nuclear energy
1
GUA - Geography - general
1
LCL - Biotopes, ecosystems
1
LCM - Terrestrial ecology
1
LCP - Limnology
1
LGR - Animal physiology
1
PAE - Physics - general interest
1
THA - Mechanical engineering - general
1
TKB - Civil engineering - buildings
1
UCJ - Environmental protection - general aspects
1
YFD - Public service legislation
1
YPD - Business economics
1
YPG - Business management
1
YPGK - Marketing
1
YPH - Secretarial work, office management
1
YRC - Technology and society
1
YZA - Politics, political science
1