Classification
620 - Engineering & allied operations
209
602 - Miscellany
149
690 - Buildings
93
671 - Metalworking & primary metal products
83
000 - Computer science, information & general works
82
624 - Civil engineering
76
621 - Applied physics
51
658 - General management
49
697 - Heating, ventilating & air-conditioning
35
669 - Metallurgy
25
530 - Physics
24
696 - Utilities
24
005 - Computer programming, programs & data
23
600 - Technology
21
670 - Manufacturing
20
681 - Precision instruments & other devices
20
665 - Industrial oils, fats, waxes & gases
17
660 - Chemical engineering
16
674 - Lumber processing, wood products & cork
14
693 - Specific materials & purposes
14
540 - Chemistry & allied sciences
13
629 - Other branches of engineering
13
628 - Sanitary & municipal engineering
9
001 - Knowledge
8
340 - Law
8
352 - General considerations of public administration
8
004 - Data processing & computer science
7
650 - Management & auxiliary services
7
539 - Modern physics
6
610 - Medicine & health
6
502 - Miscellany
5
536 - Heat
5
625 - Engineering of railroads & roads
5
651 - Office services
5
020 - Library & information sciences
4
363 - Other social problems & services
4
521 - Celestial mechanics
4
570 - Life sciences; biology
4
720 - Architecture
4
520 - Astronomy & allied sciences
3
613 - Personal health & safety
3
664 - Food technology
3
680 - Manufacture for specific uses
3
006 - Special computer methods
2
344 - Labor, social, education & cultural law
2
510 - Mathematics
2
531 - Classical mechanics; solid mechanics
2
535 - Light & infrared & ultraviolet phenomena
2
543 - Analytical chemistry
2
627 - Hydraulic engineering
2
more ...