What are the Books I need to read for UPSC/SPSC mains Optional-Public Administration?

This is the most common question that a serious aspirant for this Examination will always have in their minds. So they will keep asking everyone, what to read and what not. But to clear this doubt, You must be sure that you want Public Administration as optional because you cannot change optional subject frequently for this Examination. So be ready and set your mind for Public Administration. To clear you doubt about why PA, you need to read my post which I will share you link in my next update.