- Most simple and easy to understand discription is available in Rogers & Girolami's book "A first course in Machine Learning". Clicke here, to see screenshots of the chapters. Otherwise, I have a hard copy of the book which I am open to share.
- Bishop's "Pattern Recognition and Machine Learning" chapter 6.4, available online here.
Awesome introductory videos to GPs with non-Gaussian likelihoods:
- Alan Saul on non-Gaussian likelihoods on youtube
Paper on inducing points approximations for GP classification:
- Hensman et al. (2014) arxiv:1411.2005