“INVARIANTE AND REDUCTION OF THE CLASS Y¢ = F(x)yn , (n ¹ 0 ),UNDER STRETCHING GROUPS”. Al-Nahrain Journal of Science 11, no. 1 (April 1, 2008): 90–93. Accessed November 22, 2024. https://mail.anjs.edu.iq/index.php/anjs/article/view/1397.