Freedman, David A. (2009). Statistical Models: Theory and Practice. Cambridge University Press. стр. 26. „A simple regression equation has on the right hand side an intercept and an explanatory variable with a slope coefficient. A multiple regression equation has two or more explanatory variables on the right hand side, each with its own slope coefficient”
Rencher, Alvin C.; Christensen, William F. (2012), „Chapter 10, Multivariate regression – Section 10.1, Introduction”, Methods of Multivariate Analysis, Wiley Series in Probability and Statistics, 709 (3rd изд.), John Wiley & Sons, стр. 19, ISBN9781118391679
Yan, Xin (2009), Linear Regression Analysis: Theory and Computing, World Scientific, стр. 1—2, ISBN9789812834119, „Regression analysis ... is probably one of the oldest topics in mathematical statistics dating back to about two hundred years ago. The earliest form of the linear regression was the least squares method, which was published by Legendre in 1805, and by Gauss in 1809 ... Legendre and Gauss both applied the method to the problem of determining, from astronomical observations, the orbits of bodies about the sun.”
Foster, M. (1961). „An Application of the Wiener-Kolmogorov Smoothing Theory to Matrix Inversion”. Journal of the Society for Industrial and Applied Mathematics. 9 (3): 387. doi:10.1137/0109031.
Statistical significance of segmented linear regression with break-point using variance analysis and F-tests. Download from [1] under nr. 13, or directly as PDF : [2]