Classification
AMA - Education - general
338
AHF - Research and science
23
YPD - Business economics
15
LVE - Food science - general
14
YPH - Secretarial work, office management
14
YPB - Economy - general aspects
10
HDG - Psychology, psychiatry
8
YPJ - Accounting
7
YZA - Politics, political science
7
YRG - Technology transfer
6
AHL - Presentations, lectures, discussions
5
AHM - Theory of science
5
YBB - Law - general
4
YPGE - Human resource planning, human resource management
4
YRB - Social sciences, sociology
4
ZFA - Teaching materials, learning aids
4
AES - Universities, academies - Germany
3
AJA - Directories - general
3
YPE - Job application, job search
3
ACA - Languages, dictionaries - general
2
ACE - Germanic languages, Indo-Germanic languages
2
AHH - Universities - research
2
AHJ - Training methods
2
AHK - Scientific work
2
HAA - Medicine - reference books
2
THA - Mechanical engineering - general
2
TNQ - Nuclear reactor operation, control, measurement
2
YFF - Industrial safety regulations
2
YRA - Social studies
2
ZBB - Library staff
2
ABD - National biographic catalogues - Germany
1
AET - Universities, academies - Europe
1
AHC - Research and development, research politics - Germany
1
AHN - Media and communication science
1
AHP - Philosophy
1
AHZ - History of science and technology
1
AMAB - Industrial training, further education
1
ASEB - Book trade
1
AYA - Sciences - general aspects
1
CAD - Chemistry - comprehensive works
1
CAE - Chemistry - general
1
CAX - Chemistry - information systems, literature guides
1
DAE - Information technology - general
1
DNC - Internet
1
DTAD - MS - Word
1
DTAF - MS - Excel
1
DVA - Data and file management
1
DWI - Information management
1
DWID - Multimedia, hypertext
1
DYAA - Learning theory, adaptive systems
1
more ...