93-00 General reference works (handbooks, dictionaries, bibliographies, etc.)
93-01 Instructional exposition (textbooks, tutorial papers, etc.)
93-02 Research exposition (monographs, survey articles)
93-03 Historical (must also be assigned at least one classification number from Section 01)
93-04 Explicit machine computation and programs (not the theory of computation or programming)
93-06 Proceedings, conferences, collections, etc.
93Axx General
93Bxx Controllability, observability, and system structure
93Cxx Control systems, guided systems
93Dxx Stability
93Exx Stochastic systems and control