Classification
PAD - Physics - comprehensive works
22
TEA - Electrical engineering - general
20
UAU - Fire, fire protection, safety at the workplace, prevention of accidents
19
DSA - Computer graphics, image/photo editing
18
YPB - Economy - general aspects
14
MNLS - Computational methods - algorithms, software
13
AFG - Large scale research institutions (Helmholtz Centres)
12
CXUV - Polymers, dyes
10
FNL - Polymers, plastics - specific materials
10
YPG - Business management
10
CWA - Chemical engineering - reference books
8
TIF - Industrial ( occupational ) safety
8
YEF - Law on hazardous materials
8
AZZ - Firm index - general
7
DOF - Programming language - C, Turbo C, C# (C sharp)
7
HDF - Brain - anatomy, function, disorders
7
THA - Mechanical engineering - general
7
UVC - Environmental chemicals, hazardous materials - general aspects
7
YUC - Comprehensive statistical data
7
ETF - Fuel cells - general
6
EVA - Energy demand, energy supply - comprehensive works
6
YFF - Industrial safety regulations
6
YRA - Social studies
6
ACA - Languages, dictionaries - general
5
CAU - Laboratory and safety engineering in chemistry
5
DKAE - Windows
5
DNC - Internet
5
EHA - Renewable energy sources
5
FNK - Plastics - application, engineering aspects
5
LLE - Protein chemistry - general aspects
5
PLA - Astrosciences - general
5
THJ - Machining
5
TKD - Air conditioning, refrigeration
5
AHF - Research and science
4
EAA - Energy - reference books
4
PBA - Quantum theory
4
TBB - Electronics - theory
4
TEDF - Electric power application
4
ACE - Germanic languages, Indo-Germanic languages
3
ALH - Works of scientists and Nobel prize winners
3
AXN - Phrase books, language courses
3
DUA - Text and document processing
3
DZE - Data privacy, data security
3
E
3
EIA - Solar energy - general
3
FAP - Advanced materials - development and applications
3
HBH - Anatomy and cytology of man
3
LKH - Biochemistry - methods
3
LMH - Biophysics - methods
3
LWE - Agriculture - general aspects
3
more ...