16XX 


Associative rings and algebras {For the commutative case, see 13XX} 

16Kxx 

Division rings and semisimple Artin rings [See also 12E15, 15A30] 


16K20 
Finitedimensional {For crossed products, see 16S35} 


16K40 
Infinitedimensional and general 


16K50 
Brauer groups [See also 12G05, 14F22] 


16K99 
None of the above, but in this section 