LI W-T, CHENG S-S. AN OSCILLATiON THEOREM FOR A NEUTRAL DIFFERENCE EQUATION WITH POSITIVE AND NEGATIVE COEFFICIENTS. Tamkang J. Math. [Internet]. 1999 Mar. 1 [cited 2024 Dec. 22];30(1):39-46. Available from: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4204