In last couple of months, one of the most popular CCIE R&S training vendor in market - IP EXPERT released couple of books covering R&S blueprint technologies. Which I personally feel is a big effort. Since writing books not only takes time but also those should be user friendly as well. Otherwise there are always choices in terms of books. The best part about IPX books is that they not explain you technology in a very simple manner but also focus on configuration examples to make sure you really understand the concepts and also focus heavily on troubleshooting. Troubleshooting is I guess the part which most book vendors fail to cover or help you as reader to build step by step logical approach.
So far they have released four books under this series and I wish they will keep doing it for rest of important R&S technology domains.