19XX 


$K$theory [See also 16E20, 18F25] 


1900 
General reference works (handbooks, dictionaries, bibliographies, etc.) 


1901 
Instructional exposition (textbooks, tutorial papers, etc.) 


1902 
Research exposition (monographs, survey articles) 


1903 
Historical (must also be assigned at least one classification number from Section 01) 


1904 
Explicit machine computation and programs (not the theory of computation or programming) 


1906 
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 