Genre
- Congresses 106 canlyniadau
- Handbooks, manuals, etc 22 canlyniadau
- Periodicals 10 canlyniadau
- Encyclopedias 4 canlyniadau
- Biography 3 canlyniadau
- Textbooks 3 canlyniadau
- Atlases 2 canlyniadau
- Catalogs 2 canlyniadau
- Dictionaries 2 canlyniadau
- Juvenile literature 2 canlyniadau
- Miscellanea 2 canlyniadau
- Problems, exercises, etc 2 canlyniadau
- Anecdotes 1 canlyniadau
- Archives 1 canlyniadau
- Case studies 1 canlyniadau
- Charts, diagrams, etc 1 canlyniadau
- Maps 1 canlyniadau
- Observations 1 canlyniadau
- Outlines, syllabi, etc 1 canlyniadau
- Popular works 1 canlyniadau
- Statistics 1 canlyniadau