Hello Moazzam,

Good to see you here. Check www.bn.com www.amazon.com www.kentrotman.com http://www.safaripress.com/ and www.bookfinder.com all of whom should have books on the subject. Delivery to Pakistan may be expensive, though.

There are several experts whose books you could look for including today's masters like George Digweed and Mike Yardley and yesteryear's greats like Gough Thomas etc.

Now I'll stand back and let the more experienced members here step in with their own suggestions.

Good hunting!