1. Ackermann, W.: Solvable Cases of the Decision Problem. North Holland, Amsterdam (1954)
2. Lecture Notes in Computer Science;P.B. Andrews,1990
3. Lecture Notes in Computer Science;K. Arkoudas,2004
4. Baader, F., Calvanese, D., McGuinness, D., Nardi, D., Patel-Schneider, P.(ed.): The Description Logic Handbook: Theory, Implementation and Applications. In: CUP (2003)
5. Börger, E., Grädel, E., Gurevich, Y.: The Classical Decision Problem. Springer, Heidelberg (1997)