[1] C. Eckart, G. Young: The approximation of one matrix by another of lower rank. Psychometrika, 1 (1936), pp. 211-218. DOI 10.1007/BF02288367

[2] K. Fan, A. Hoffman: Some metric inequalities in the space of matrices. Proc. Anier. Math. Soc., 6 (1955), pp. 111-116. DOI 10.1090/S0002-9939-1955-0067841-7 | MR 0067841 | Zbl 0064.01402

[3] J. Francis: The QR transformation. A unitary analogue to the LR transformation. Comput. J., 4 (1961, 1962), pp. 265-271. DOI 10.1093/comjnl/4.3.265 | MR 0130111 | Zbl 0104.34304

[4] G. Golub, W. Kahan: Calculating the singular values and pseudoinverse of a matrix. J. SIAM Numer. Anal. Ser. B, 2 (1965), pp. 205-224. MR 0183105

[5] B. Green: The orthogonal approximation of an oblique structure in factor analysis. Psychometrika, 17 (1952), pp. 429-440. DOI 10.1007/BF02288918 | MR 0053057 | Zbl 0049.37601

[6] C. Lanczos: Linear Differential Operators. Van Nostrand, London, 1961, Chap. 3. MR 0129153 | Zbl 0111.08305

[7] L. Mirsky: Symmetric gauge functions and unitarily invariant norms. Quart. J. Math. Oxford (2), 11 (1960), pp. 50-59. DOI 10.1093/qmath/11.1.50 | MR 0114821 | Zbl 0105.01101

[8] R. Penrose: A generalized inverse for matrices. Proc. Cambridge Philos. Soc., 51 (1955), pp. 406-413. DOI 10.1017/S0305004100030401 | MR 0069793 | Zbl 0065.24603

[9] P. Schönemann: A generalized solution of the orthogonal procrustes problem. Psychometrika, 31 (1966), pp. 1-10. DOI 10.1007/BF02289451 | MR 0215870