MSC results for "19"

**19-00**(1986-now) General reference works (handbooks, dictionaries, bibliographies, etc.)

**19-01**(1986-now) Instructional exposition (textbooks, tutorial papers, etc.)

**19-02**(1986-now) Research exposition (monographs, survey articles)

**19-03**(1986-now) Historical (must also be assigned at least one classification number from Section 01)

**19-04**(1986-now) Explicit machine computation and programs (not the theory of computation or programming)

**19-06**(1986-now) Proceedings, conferences, collections, etc.

**19J**(1991-now) Obstructions from topology