1. B.P.P.P. Divn., Central Building Research Institute, Roorkee-247 667, U.A., India
2. Department of Mathematics, Bhaskaracharya College of Applied Sciences, (University of Delhi), Sector-2, Phase-1, Dwarka, New Delhi-110045, India
3. Ex-Principal, D.N. College, Meerut, U.P., India