Hello dear student !

There are so many books which are very helpful for comedk preparation of old solved question papers. These are also not that expensive and are quite affordable and are easily available in the shopping sites.

Some of them are listed below :

Sure success Comed-K by B Ramgopal

Comed-K Dental Buster by Jeevitha Murugesh and Narendranatha Reddy

COMEDK Chapterwise solutions by MTG learning media

Hope this will help you!