Imieliński, Tomasz; Lipski, Witold jun. Incomplete information in relational databases. (English) Zbl 0632.68094 J. Assoc. Comput. Mach. 31, 761-791 (1984). Cited in 64 Documents MSC: 68P20 Information storage and retrieval of data Keywords:relational database; incomplete information; null values; marked nulls; relational algebra; query language semantics; query processing PDFBibTeX XMLCite \textit{T. Imieliński} and \textit{W. Lipski jun.}, J. Assoc. Comput. Mach. 31, 761--791 (1984; Zbl 0632.68094) Full Text: DOI