Neumann, Frank Algorithms and Complexity, MPI for Informatics, Max Planck Society;
Diedrich, F., Kehden, B., & Neumann, F. (2008). Multi-objective Problems in Terms of Relational Algebra. In R. Berghammer, B. Möller, & G. Struth (Eds.), Relations and Kleene Algebra in Computer Science 2008 (pp. 84-98). Berlin: Springer. doi:10.1007/978-3-540-78913-0_8.