Srisawat, Somnuk, and Wanna Sriprad. 2017. “On Some Identites and Generating Functions for (s,t)-Pell and (s,t)-Pell-Lucas Numbers”. Progress in Applied Science and Technology 7 (2). Thailand:194-99. https://ph02.tci-thaijo.org/index.php/past/article/view/243074.