الأصناف الرئيسية
2X
الأقسام
الفروع
- 600Technology1
- 601Philosophy & theory
- 602Miscellany
- 603Dictionaries & encyclopedias
- 604Special topics
- 605Serial publications
- 606Organizations
- 607Education, research & related topics
- 608Inventions & patents
- 609Historical, geographic & persons treatment