Classification
551 - Geology, hydrology & meteorology
1,431
550 - Earth sciences
1,293
363 - Other social problems & services
746
910 - Geography & travel
735
624 - Civil engineering
700
333 - Economics of land & energy
632
620 - Engineering & allied operations
568
700 - The arts; fine & decorative arts
539
520 - Astronomy & allied sciences
530
621 - Applied physics
458
500 - Natural sciences & mathematics
456
519 - Probabilities & applied mathematics
429
600 - Technology
354
530 - Physics
346
330 - Economics
339
577 - Ecology
325
610 - Medicine & health
284
523 - Specific celestial bodies & phenomena
248
000 - Computer science, information & general works
220
900 - History & geography
203
629 - Other branches of engineering
194
300 - Social sciences
178
320 - Political science
174
576 - Genetics & evolution
172
304 - Factors affecting social behavior
160
006 - Special computer methods
157
005 - Computer programming, programs & data
150
004 - Data processing & computer science
148
540 - Chemistry & allied sciences
143
820 - English & Old English literatures
134
630 - Agriculture & related technologies
132
526 - Mathematical geography
129
658 - General management
126
580 - Plants (Botany)
120
549 - Mineralogy
105
570 - Life sciences; biology
91
581 - Specific topics in natural history
88
380 - Commerce, communications & transportation
83
140 - Specific philosophical schools
82
301 - Sociology & anthropology
82
541 - Physical chemistry
77
338 - Production
74
631 - Techniques, equipment & materials
73
200 - Religion
67
230 - Christianity & Christian theology
67
628 - Sanitary & municipal engineering
67
001 - Knowledge
65
100 - Philosophy & psychology
63
003 - Systems
62
340 - Law
62
more ...