kamal garg is good and simple...just get the latest and study it many times over.....study materail is good but u must get the latest and see that mistakes of past study materails are not repeated....
padhukas or vinod agarwal is good but u must have lots of time to finish it...i wont advice padhukas because u have other subjects to cover...
Finally go for some auditing compiler...kamal garg latest also has solved paper of last 5-10 attempts...so be thorough in it...
my friend who adopted this strategy got 74 marks and she even got a rank...as in m,ics too she got more than 80%!