PageHeader : Funkcialaj Ekvacioj, 34 (1991) 223-239 Title : Oscillation Criteria for Second Order Title : Difference Equation AuthorInfo : By AuthorInfo : Sui Sun CHENG* , Tze Cheung YAN and Horng Jaan Li AuthorInfo : ( Tsing Hua University and Chen Kwok Technical School, Republic of China) section : 1. Introduction section : 2. Preparatory lemmas section : 3. Oscillation criteria section : 4. Conditional oscillation criteria section : References