Genre
- Congresses 5.049 Treffer
- Periodicals 738 Treffer
- Biography 520 Treffer
- Juvenile literature 517 Treffer
- Problems, exercises, etc 300 Treffer
- Textbooks 260 Treffer
- Handbooks, manuals, etc 233 Treffer
- Popular works 232 Treffer
- Classification 197 Treffer
- Laboratory manuals 170 Treffer
- Identification 157 Treffer
- Dictionaries 143 Treffer
- Early works to 1800 143 Treffer
- Pictorial works 130 Treffer
- Encyclopedias 100 Treffer
- Tables 100 Treffer
- Miscellanea 95 Treffer
- Atlases 82 Treffer
- Case studies 51 Treffer
- Nomenclature 47 Treffer
- Maps 44 Treffer
- Observations 36 Treffer
- Anecdotes 35 Treffer
- Bibliography 34 Treffer
- Databases 31 Treffer
- Catalogs 27 Treffer
- Correspondence 27 Treffer
- Observers' manuals 24 Treffer
- Folklore 21 Treffer
- Charts, diagrams, etc 19 Treffer
- Terminology 19 Treffer
- Outlines, syllabi, etc 17 Treffer
- Abstracts 15 Treffer
- Study guides 15 Treffer
- Examinations, questions, etc 14 Treffer
- History 12 Treffer
- Interviews 12 Treffer
- Photographs from space 12 Treffer
- Sources 12 Treffer
- Directories 10 Treffer
- Guidebooks 10 Treffer
- Pre-Linnean works 10 Treffer
- Catalogs and collections 9 Treffer
- Humor 9 Treffer
- Juvenile fiction 9 Treffer
- Quotations, maxims, etc 9 Treffer
- Nomenclature (Popular) 8 Treffer
- Outdoor books 8 Treffer
- Indexes 7 Treffer
- Amateurs' manuals 6 Treffer mehr …