Since you're simply looking to reference to these papers, here is a list:

 1. Tikhonov, Andrey Nikolayevich (1943). "Об устойчивости обратных задач" [On the stability of inverse problems]. Doklady Akademii Nauk SSSR. 39 (5): 195–198.
 2. Tikhonov, A. N. (1963). "О решении некорректно поставленных задач и методе регуляризации". Doklady Akademii Nauk SSSR. 151: 501–504.. Translated in "Solution of incorrectly formulated problems and the regularization method". Soviet Mathematics. 4: 1035–1038.
 3. Hoerl AE, 1962, Application of ridge analysis to regression problems, Chemical Engineering Progress, 1958, 54–59.
 4. Arthur E. Hoerl; Robert W. Kennard (1970). "Ridge regression: Biased estimation for nonorthogonal problems". Technometrics. 12 (1): 55–67. doi:10.2307/1267351.
 5. Tibshirani, Robert (1996). "Regression Shrinkage and Selection via the Lasso" (PostScript). Journal of the Royal Statistical Society, Series B. 58 (1): 267–288. MR 1379242
 6. Zou, H. and Hastie, T. (2005). Regularization and variable
selection via the elastic net. Journal of the Royal Statistical Society, Series B. 67: pp. 301–320.