Algorithmus Biology Mathematical models Biology and other natural sciences Biology and other natural sciences -- Other natural sciences (should also be assigned at least one other classification number in this section) -- Other natural sciences (should also be assigned at least one other classification number in section 92) Biomathematics Biomathematik Coding theory Textbooks Combinatorics -- Graph theory -- Graph theory Computer science -- Computing methodologies and applications -- Computing methodologies and applications Cryptography History Textbooks Cryptography Mathematics Textbooks Cryptography Textbooks Data encryption (Computer science) Textbooks Elektrotechnik General -- General and miscellaneous specific topics -- General applied mathematics General -- General and miscellaneous specific topics -- Mathematics for nonmathematicians (engineering, social sciences, etc.) General -- General and miscellaneous specific topics -- Recreational mathematics Geschichte Graph Hochschulschrift Informatik Komplexität Kryptologie Lehrbuch Mathematics education Mathematik Mathematikunterricht Mathematisches Modell Systems theory; control -- General -- Mathematical modeling (models of systems, model-matching, etc.)