19-XX

19-00 General reference works (handbooks, dictionaries, bibliographies, etc.)
19-01 Instructional exposition (textbooks, tutorial papers, etc.)
19-02 Research exposition (monographs, survey articles)
19-03 Historical (must also be assigned at least one classification number from Section 01)
19-04 Explicit machine computation and programs (not the theory of computation or programming)
19-06 Proceedings, conferences, collections, etc.
19Axx Grothendieck groups and $K_0$ [See also 13D15, 18F30]
19Bxx Whitehead groups and $K_1$
19Cxx Steinberg groups and $K_2$
19Dxx Higher algebraic $K$-theory
19Exx $K$-theory in geometry
19Fxx $K$-theory in number theory [See also 11R70, 11S70]
19Gxx $K$-theory of forms [See also 11Exx]
19Jxx Obstructions from topology
19Kxx $K$-theory and operator algebras [See mainly 46L80, and also 46M20]
19Lxx Topological $K$-theory [See also 55N15, 55R50, 55S25]
19Mxx Miscellaneous applications of $K$-theory