Classification
900 - History & geography
22
930 - History of ancient world to ca. 499
8
520 - Astronomy & allied sciences
7
301 - Sociology & anthropology
5
720 - Architecture
4
200 - Religion
3
320 - Political science
3
306 - Culture & institutions
2
510 - Mathematics
2
576 - Genetics & evolution
2
577 - Ecology
2
581 - Specific topics in natural history
2
700 - The arts; fine & decorative arts
2
140 - Specific philosophical schools
1
299 - Religions not provided for elsewhere
1
304 - Factors affecting social behavior
1
330 - Economics
1
333 - Economics of land & energy
1
340 - Law
1
363 - Other social problems & services
1
370 - Education
1
500 - Natural sciences & mathematics
1
571 - Physiology & related subjects
1
600 - Technology
1
610 - Medicine & health
1
616 - Diseases
1
620 - Engineering & allied operations
1
631 - Techniques, equipment & materials
1
634 - Orchards, fruits & forestry
1
690 - Buildings
1
738 - Ceramic arts
1
820 - English & Old English literatures
1
970 - History of North America
1
984 - Bolivia
1
985 - Peru
1