For IDT reading Bangar is more than enough. During exam refer RTP's and supplementry study papers of ICAI of immediately previous attempt as well as current atempt because many time 50%-60%questions are set ot from these books only.
I don't agree..I found Dippak Sir's book best even for self study..I did self study from his book..you got crystal clarity once you read his book..go for DIPPAK GUPTA Sir's books