Ahmet Hamal
      The completeness of S4
      International Mathematical Forum, Vol. 9, 2014, no. 9, 437-448
      http://dx.doi.org/10.12988/imf.2014.4123

Copyright © 2014 Ahmet Hamal. This article is distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.