1. Barthélemy, J. P., & Guénoche, A. (1991). Tree and proximity representations. Chichester: Wiley.
2. Boyle, J. P., & Dykstra, R. L. (1985). A method for finding projections onto the intersection of convex sets in Hilbert spaces. In R. L. Dykstra, R. Robertson, & F. T. Wright (Eds.), Advances in order restricted inference (Lecture Notes in Statistics, Vol 37) (pp. 28–47). Berlin: Springer.
3. Carroll, J. D. (1976). Spatial, non-spatial and hybrid models for scaling. Psychometrika, 41, 439–463.
4. Carroll, J. D., & Pruzansky, S. (1980). Discrete and hybrid scaling models. In E. Lantermann & H. Feger (Eds.), Similarity and choice (pp. 108–139). Bern: Huber.
5. Carroll, J. D., Clark, L. A., & DeSarbo, W. S. (1984). The representation of three-way proximities data by single and multiple tree structure models. Journal of Classification, 1, 25–74.