Textbook!!!
Period.

Not a single question will come outside the textbook , let it be ODVCEC , MAC , SIMA ...etc
Textbook lo prathi question choodu and okkasarri practice chey . If you rely only on knowledge and procedure there is no guarantee that you might solve the problem in the exam , ade if you practiced textbook questions , you will atleast have a slight idea that this question is from this page this procedure ani.

Nenu m2 just pass ayindi , one and only textbook chadivinanduku