M. Heule, M. Seidl, A. Biere:
"A Unified Proof System for QBF Preprocessing";
Vortrag: IJCAR, Wien; 19.07.2014 - 22.07.2014; in: "Proceedings of the 7th International Joint Conference on Automated Reasoning", LNCS/Springer, 8562 (2014), ISBN: 978-3-319-08587-6; S. 91 - 106.
http://link.springer.com/chapter/10.1007%2F978-3-319-08587-6_7