@incollection{DBLP:books/bc/tanselCGSS93/Lorentzos93,
  author    = {Nikos A. Lorentzos},
  title     = {The Interval-extended Relational Model and Its Applications
               to Valid-time Databases},
  booktitle = {Temporal Databases},
  year      = {1993},
  pages     = {67-91},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}