1. Long waves, growth retarding factors and paradigms of the new upswing;Baaske,1987
2. Explorative Datenanalyse—eine Übersicht;Bock;Allgemeines Statist. Arch.,1984
3. Biplot display of multivariate matrices for inspection of data and diagnosis;Gabriel,1981
4. Graphische Darstellung von Matrizen durch das Biplot;Gabriel;EDV Med. u. Biol.,1976