الأصناف الرئيسية
2X
الأقسام
الفروع
- 500Natural sciences & mathematics11
- 501Philosophy & theory1
- 502Miscellany
- 503Dictionaries & encyclopedias
- 504[Unassigned]
- 505Serial publications2
- 506Organizations & management
- 507Education, research & related topics1
- 508Natural history
- 509Historical, geographic & persons treatment