Then you must increase your writing skills by using simple english and write the keypoints in an attractive way...
Yes i am concentrating on my skills right now.
Local authors covers most key points and hence the people following it get good scores when they read the small book thoroughly.
My suggestion is to use prescribed books first,and when is no time you can go for local author book in the last minute.
Since most of the people study during the last minute, they prefer local authors :p