Contact Information:

Abba B. Gumel,
Department of Mathematics,
University of Manitoba, R3T 2N2, Canada.
Email: gumelab@cc.umanitoba.ca
Tel: +1(204): 4747486
Fax: +1(204) 4747611

Edward Lungu,
Department of Mathematics,
P/Bag UB 00704, Gaborone, Botswana.
Email: lunguem@mopipi.ub.bw