18Fxx
18E | 
18 | 
18G 18Fxx | 18E | 18 | 18G |
| 18F05 | Local categories and functors |
| 18F10 | Grothendieck topologies [See also 14F20] |
| 18F15 | Abstract manifolds and fiber bundles [See also 55Rxx, 57Pxx] |
| 18F20 | Presheaves and sheaves [See also 14F05, 32C35, 32L10, 54B40, 55N30] |
| 18F25 | Algebraic K-theory and L-theory [See also 11Exx, 11R70, 11S70, 12-XX, 13D15, 14Cxx, 16E20, 19-XX, 46L80, 57R65, 57R67] |
| 18F30 | Grothendieck groups [See also 13D15, 16E20, 19Axx] |
| 18F99 | None of the above, but in this section |