Genre
- Congresses 31 canlyniadau
- Handbooks, manuals, etc 20 canlyniadau
- Case studies 11 canlyniadau
- Cross-cultural studies 2 canlyniadau
- Problems, exercises, etc 2 canlyniadau
- Classification 1 canlyniadau
- Early works to 1800 1 canlyniadau
- Examinations, questions, etc 1 canlyniadau
- Guides, manuels, etc 1 canlyniadau
- Handbook 1 canlyniadau
- Handbooks and manuals 1 canlyniadau
- Identification 1 canlyniadau
- Maps 1 canlyniadau
- Observations 1 canlyniadau
- Periodicals 1 canlyniadau
- Textbooks 1 canlyniadau