97Uxx Educational material and media. Educational technology
- 97U10 Comprehensive works
- 97U20 Textbooks. Textbook research
- 97U30 Teacher`s manuals and planning aids
- 97U40 Problem books. Competitions. Examinations
- 97U50 Computer assisted instruction; e-learning
- 97U60 Manipulative materials
- 97U70 Technological tools. Calculators (1)
- 97U80 Audiovisual media
- 97U99 None of the above, but in this section