#Note : Scoring is easy in this subject, if you practice well,.... Scoring 70+ is relatively simple.
Books : Among the Local Author's .. I would suggest go for Techmx - Dilip Kumar Sultania. The book lacks sufficent amount of examples, but will suffice and is better when compared to the other available books in the market.
Among Foreign author's : I would only suggest
Introduction to Automata Theory,Languages and Computation - Jeffrey, Hopcroft
Download the Ebooks using the Torrents: