Vlad P. Shmerko Svetlana N. Yanushkevich Vitaly G. Levashenko Test Pattern Generation for Combinatorial Multi-Valued Networks Based on Generalized D-Algorithm. 139-144 1997 ISMVL http://computer.org/proceedings/ismvl/7910/79100139abs.htm db/conf/ismvl/ismvl1997.html#ShmerkoYL97