CHENG, SUI SUN, SHENG-LI XIE, and BING-GEN ZHANG. “QUALITATIVE THEORY OF PARTIAL DIFFERENCE EQUATIONS (III): FORCED OSCILLATIONS OF PARABOLIC TYPE PARTIAL DIFFERENCE EQUATIONS”. Tamkang Journal of Mathematics 26, no. 2 (June 1, 1995): 177–192. Accessed October 3, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4395.