The best reference book for prepare for CA IPCC of Taxation is by T N Manoharan. It is the best book for self-study. The concepts of the direct tax are clearly stated in this book which helps u in easy understanding. If that information is not enough, I will recommend a service where to buy essays or blog, which addresses these issues.
I used online services more than to books. I think it is more convenient and faster way to learn.
For instance, a writer-elite.com writer-elite.com I found a lot of useful information.
It was very helpful while I was doing my research. They provide useful writing tips