A bit more modern than what you quote is de Boor, C. (1978) A Practical Guide to Splines, Springer Verlag. An efficient algorithm for smoothing splines is given by Hutchinson, M.F. and de Hoog, F.R. (1985) Smoothing Noisy Data with Spline Functions, Numerische Mathematik, 47, p. 99-106 (see also Hutchinson, M.F. (1986) Cubic Spline Data Smoother, Transactions on Mathematical Software, vol. 12, 150-153;
you will find the FORTRAN source of the algortihm in http://calgo.acm.org).
Note also that the Kalman filter can be a good tool to fit some types of splines; see for instance an answer I gave sometime ago on Kalman filter vs. smoothing splines. You will find much relevant information if you search here in CrossValidated using "splines" as a tag.