1. Eckhart, Carl, andYoung, Gale, “The approximation of one matrix by another of lower rank,”Psychometrika, 1936,1, 211–218.
2. Mosier, C. I., “On rotation to a known simple structure,” to appear inPsychometrika.
3. Thurstone, L. L.,The Vectors of Mind, Chicago: Univ. of Chicago Press, 1935, pp. xv, 266.