Degrees of freedom (statistics) (English Wikipedia)

Trevor Hastie, Robert Tibshirani, Jerome H. Friedman (2009), The elements of statistical learning: data mining, inference, and prediction, 2nd ed., 746 p. ISBN 978-0-387-84857-0, doi:10.1007/978-0-387-84858-7, [1] (eq.(5.16))
Fox, J. (2000). Nonparametric Simple Regression: Smoothing Scatterplots. Quantitative Applications in the Social Sciences. Vol. 130. SAGE Publications. p. 58. ISBN 978-0-7619-1585-0. Retrieved 2020-08-28.
Catherine Loader (1999), Local regression and likelihood, ISBN 978-0-387-98775-0, doi:10.1007/b98858, (eq.(2.18), p. 30)
Trevor Hastie, Robert Tibshirani (1990), Generalized additive models, CRC Press, (p. 54) and (eq.(B.1), p. 305))
Simon N. Wood (2006), Generalized additive models: an introduction with R, CRC Press, (eq.(4,14), p. 172)
James S. Hodges (2014), Richly Parameterized Linear Models, CRC Press. [2]
Peter J. Green, B. W. Silverman (1994), Nonparametric regression and generalized linear models: a roughness penalty approach, CRC Press (eq.(3.15), p. 37)

davidmlane.com (Global: low place; English: low place)

Lane, David M. "Degrees of Freedom". HyperStat Online. Statistics Solutions. Retrieved 2008-08-21.

Walker, H. M. (April 1940). "Degrees of Freedom" (PDF). Journal of Educational Psychology. 31 (4): 253–269. doi:10.1037/h0054588.
Student (March 1908). "The Probable Error of a Mean". Biometrika. 6 (1): 1–25. doi:10.2307/2331554. JSTOR 2331554.
Fisher, R. A. (January 1922). "On the Interpretation of χ2 from Contingency Tables, and the Calculation of P". Journal of the Royal Statistical Society. 85 (1): 87–94. doi:10.2307/2340521. JSTOR 2340521.
Cichoń, Mariusz (2020-06-01). "Reporting statistical methods and outcome of statistical analyses in research articles". Pharmacological Reports. 72 (3): 481–485. doi:10.1007/s43440-020-00110-5. ISSN 2299-5684. PMID 32542585.
Trevor Hastie, Robert Tibshirani, Jerome H. Friedman (2009), The elements of statistical learning: data mining, inference, and prediction, 2nd ed., 746 p. ISBN 978-0-387-84857-0, doi:10.1007/978-0-387-84858-7, [1] (eq.(5.16))
Catherine Loader (1999), Local regression and likelihood, ISBN 978-0-387-98775-0, doi:10.1007/b98858, (eq.(2.18), p. 30)
D. Dong, T. A. Herring and R. W. King (1997), Estimating regional deformation from a combination of space and terrestrial geodetic data, J. Geodesy, 72 (4), 200–214, doi:10.1007/s001900050161 (eq.(27), p. 205)

Student (March 1908). "The Probable Error of a Mean". Biometrika. 6 (1): 1–25. doi:10.2307/2331554. JSTOR 2331554.
Fisher, R. A. (January 1922). "On the Interpretation of χ2 from Contingency Tables, and the Calculation of P". Journal of the Royal Statistical Society. 85 (1): 87–94. doi:10.2307/2340521. JSTOR 2340521.
Ye, J. (1998), "On Measuring and Correcting the Effects of Data Mining and Model Selection", Journal of the American Statistical Association, 93 (441), 120–131. JSTOR 2669609 (eq.(7))
H. Theil (1963), "On the Use of Incomplete Prior Information in Regression Analysis", Journal of the American Statistical Association, 58 (302), 401–414 JSTOR 2283275 (eq.(5.19)–(5.20))

Walker, H. M. (April 1940). "Degrees of Freedom" (PDF). Journal of Educational Psychology. 31 (4): 253–269. doi:10.1037/h0054588.