Hierarchies of Data Base Languages: An Example. - Klaus-Dieter Krägeloh; Peter C. Lockemann (Inf. Syst., 1975)

Top-Down Optimization in Multi-Level Data Base Systems. - Klaus-Dieter Krägeloh; Peter C. Lockemann (IFIP Congress, 1977)

Access to Data Base Systems via Natural Language. - Klaus-Dieter Krägeloh; Peter C. Lockemann (Natural Language Communication with Computers, 1978)