Classification
900 - History & geography
4
100 - Philosophy & psychology
2
300 - Social sciences
2
140 - Specific philosophical schools
1
301 - Sociology & anthropology
1
363 - Other social problems & services
1
370 - Education
1
400 - Language
1
410 - Linguistics
1
600 - Technology
1
620 - Engineering & allied operations
1
700 - The arts; fine & decorative arts
1
800 - Literature & rhetoric
1