JUN, Y. B., Department of Mathematics, Gyeongsang National University, Chinju 660-701, Korea. Jun, Yuan JUNEJA, O. P. , Department of Mathematics, Kakatiya Unive1·sity, Warangal-506009, A. P. India. JUNG, JONG SOO, Department of Mathematics, Dong-A University, Pusan 607-714, Korea.
