Classification
330 - Economics
451
333 - Economics of land & energy
357
700 - The arts; fine & decorative arts
318
610 - Medicine & health
264
320 - Political science
254
900 - History & geography
235
300 - Social sciences
232
577 - Ecology
213
000 - Computer science, information & general works
212
363 - Other social problems & services
206
200 - Religion
177
600 - Technology
152
140 - Specific philosophical schools
133
370 - Education
126
551 - Geology, hydrology & meteorology
117
301 - Sociology & anthropology
99
155 - Differential & developmental psychology
98
580 - Plants (Botany)
98
380 - Commerce, communications & transportation
93
581 - Specific topics in natural history
93
340 - Law
87
304 - Factors affecting social behavior
86
620 - Engineering & allied operations
85
630 - Agriculture & related technologies
76
361 - Social problems & social welfare in general
70
100 - Philosophy & psychology
65
800 - Literature & rhetoric
54
576 - Genetics & evolution
53
658 - General management
50
720 - Architecture
50
306 - Culture & institutions
48
297 - Islam, Babism & Bahai Faith
43
338 - Production
43
307 - Communities
42
400 - Language
40
500 - Natural sciences & mathematics
39
570 - Life sciences; biology
28
579 - Microorganisms, fungi & algae
26
305 - Social groups
25
910 - Geography & travel
25
343 - Military, tax, trade & industrial law
24
296 - Judaism
23
540 - Chemistry & allied sciences
23
170 - Ethics
22
302 - Social interaction
20
410 - Linguistics
20
616 - Diseases
20
360 - Social problems & services; associations
19
364 - Criminology
18
414 - Phonology & phonetics
18
more ...