International Relations: Ikram Rabbani's IR book and World Politics: Trend and Transformation by Charles Kegley
Journalsm and Mass Communication: Journalism For All By Dr Mehdi Hassan, Mass Communication by Imtiaz Shahid.
Mercantile Law: Mercantile Law by H H Khan, Mercantile Law of Khalid Mehmood Cheema
Business Administration: An Introduction to Business Administration by Sibtain Afza (Jahangir Publisher)
Essays by Nasir Jamal
English (Precis & Comp): To the Point English by Jahangir Publisher and Exploring the World of English by Saadat Ali Shah
Along with all these books, keep newspaper reading an indispensable part of your study.