Present Address.

INSA Honorary Scientist, Department of Mathematics

Indian Institute of Science Education and Research, Mohali

Sector 81, Knowledge City, SAS Nagar,

Punjab-140306 (INDIA)

E-mail: skhanduja@iisermohali.ac.in, sudeshkaur@yahoo.com

&

Emeritus Professor, Department of Mathematics

Panjab University,

Sector - 14, Chandigarh, 

Punjab-160014 (INDIA)

E-mail: skhanduja@iisermohali.ac.in, sudeshkaur@yahoo.com