1. On the power of magic
2. Query-Subquery Nets with Stratified Negation
3. Cao, S. T. 2016a. Methods for evaluating queries to Horn knowledge bases in first-order logic. PhD dissertation. University of Warsaw, Warsaw, Poland. Available at http://mimuw.edu.pl/~sonct/stc-thesis.pdf
4. Cao, S. T. 2016b. An illustration of Algorithm 1 on an example. Available at http://mimuw.edu.pl/~sonct/Alg1.zip