1. Van Nostrand's Scientific Encyclopedia,1976
2. The New Encyclopedia Britannica, Macropedia,1975
3. Investigation of gamna ray activity and radiological hazards of the bricks fabricated around Lahore (Pakistan);Tufali;Pak. J. Sci. Ind. Res.,1991
4. Encyclopedia of Science and Technology,1971
5. Clay resources of West Pakistan;Kazmi,1963