Here you can find the supplementary material of the manuscript:

Hernandez-Lobato, D.; Hernandez-Lobato, J. M. ; Dupont,

P. Shawe-Taylor, J.; Zemel, R.; Bartlett, P.; Pereira, F. ; Weinberger, K. (Eds.)

Robust Multi-Class Gaussian Process Classification Advances in Neural Information Processing Systems 24, 2011, 280-288

Just use the following link: Supplementary Material

The R source code of the RMGPC method described in that manuscript is avaialble in this other link: R-Code

Here you can find a toy example about how to use the code: Example-Code