A least squares algorithm for fitting an ultrametric tree to a dissimilarity matrix. - Geert De Soete (Pattern Recognit. Lett., 1984)

A Perceptual Study of the Flury-Riedwyl Faces for Graphically Displaying Multivariate Data. - Geert De Soete (Int. J. Man Mach. Stud., 1986)

Multiple trees: Fitting two or more tree structures to proximity data. - J. Douglas Carroll; Geert De Soete (Mathematical Hierarchies and Biology, 1996)