Gaussian Processes for Machine Learning, Carl Edward Rasmussen and Christopher K. I. Williams, 2006 (The MIT Press) - The comprehensive textbook on Gaussian Processes, providing a detailed treatment of their theory and applications in machine learning.
Pattern Recognition and Machine Learning, Christopher Bishop, 2006 (Springer) - A widely used textbook covering fundamental machine learning concepts, including a dedicated chapter on Gaussian Processes and the distinction between parametric and non-parametric models.
Bayesian Nonparametrics, Jayanta K. Ghosh and R. V. Ramamoorthi, 2003 (Springer Science & Business Media)DOI: 10.1007/b97500 - A foundational text introducing the theoretical foundations of Bayesian nonparametric modeling, including concepts like priors over infinite-dimensional objects.