Ihlemann, Carsten Automation of Logic, MPI for Informatics, Max Planck Society;
Sofronie-Stokkermans, Viorica Automation of Logic, MPI for Informatics, Max Planck Society;
http://www.avacs.org/Publikationen/Open/avacs_technical_report_060.pdf (Any fulltext)
Ihlemann, C., & Sofronie-Stokkermans, V.(2010). On Hierarchical Reasoning in Combinations of Theories (ATR60). SFB/TR 14 AVACS.