@ neelumgulchaudhry
I,my being the masters with geography would suggest you the following books:
Physical Geography by Iftikhar Akram Ch.
Jahangir Exam Cram Series,Top 20Qs
Physical Geo by de.Blij
Human Geo by de.Blij
(if I be honest,the former two books thoroughly covers the syllabi of CSS goegraphy n the latter two books would substantiate your knowledge)
In my humble opinion,drawing of maps and diagrams where requires n provision of data in tabular form is the key to get v good scores in geography.
Good luck to you...
regards,
IBRm
DMG(37th common)