Ganzinger, Harald Programming Logics, MPI for Informatics, Max Planck Society;
1-s2.0-030439759090105Q-main.pdf (Publisher version), 2MB
Ganzinger, H. (1991). Order-sorted Completion: The Many-sorted Way. Theoretical computer science, 89(1), 3-32. doi:10.1016/0304-3975(90)90105-Q.