Best book on inc. tax for practicing CA?

Hello everyone,

it has been 6 months since i started my practice.

Income tax is my favourite subject. I am also teaching Income tax in college.

i want to have deep knowledge in income tax. so i m looking for a book where many problems and case laws are given.

In CA final i referred Vinod Gupta and i liked it but i want something more not just exam oriented.

Many people are using VK singhania.

Waiting for the views of the friends/experts.