Alt, Helmut Max Planck Society;
Geffert, Viliam Max Planck Society;
Mehlhorn, Kurt Algorithms and Complexity, MPI for Informatics, Max Planck Society;
Alt, H., Geffert, V., & Mehlhorn, K. (1992). A Lower Bound for the Nondeterministic Space Complexity of Context-free Recognition. Information Processing Letters, 42(1), 25-27. doi:10.1016/0020-0190(92)90127-H.