Barth, Peter Programming Logics, MPI for Informatics, Max Planck Society;
https://rdcu.be/dr7hr (Verlagsversion)
Barth, P. (1993). Linear 0-1 Inequalities and Extended Clauses. In A. Voronkov (Ed.), Logic Programming and Automated Reasoning (pp. 40-51). Berlin, Germany: Springer.