Classification
DOL - Programming language - Python
21
AXN - Phrase books, language courses
15
AHK - Scientific work
13
CBB - Inorganic chemistry - comprehensive works
11
HDF - Brain - anatomy, function, disorders
10
PAD - Physics - comprehensive works
10
TEA - Electrical engineering - general
10
YPD - Business economics
10
YPG - Business management
10
DOR - Programming languages - JAVA, C#, Mono, .NET
9
HDS - Neurophysiology, neuroanatomy
9
PBA - Quantum theory
9
DOQ - Programming languages - Internet
8
DPA - Electronic data processing - applications
8
DUAL - Typesetting - TeX/LaTeX
8
DWA - Database systems
8
HDE - Neurology - general aspects
8
CAN - Chemistry - mathematical methods, computer applications
7
DOO - Programming language - SPSS, R, S etc.
7
DOZ - Programming languages - Other
7
FAJ - Solid state physics - introductions
7
HBC - Physiological chemistry, biochemistry
7
LRH - Cytology - methods
7
CAE - Chemistry - general
6
CHX - Chemical thermodynamics
6
DNC - Internet
6
DOFC - Programming language - C plus-plus
6
DSA - Computer graphics, image/photo editing
6
DYA - Artificial intelligence
6
HDG - Psychology, psychiatry
6
HDH - Neuropsychology
6
HPK - Special pharmacology, drug design
6
PEA - Electromagnetism
6
ACE - Germanic languages, Indo-Germanic languages
5
CAU - Laboratory and safety engineering in chemistry
5
CER - Macromolecular compounds - synthesis and reactions
5
CHA - Physical chemistry - comprehensive works
5
DKAL - Linux - operating system
5
DMC - Computer programs
5
DOE - Programming language - BASIC, Turbo BASIC, Visual BASIC
5
DOF - Programming language - C, Turbo C, C# (C sharp)
5
EXA - Energy policy
5
FNF - Polymer science - general aspects
5
HCR - Imaging techniques in medicine
5
LEN - Plant physiology
5
LOH - Genetics - methods
5
LTU - Genetic engineering
5
PCB - Statistical physics
5
PGA - Plasma physics
5
TCL - High frequency engineering
5
more ...