SIMONYAN, E. A. AN EXTENTION OF THE LITTLE’S FORMULA. Proceedings of the YSU A: Physical and Mathematical Sciences, Yerevan, Armenia, v. 37, n. 3 (202), p. 25–29, 2003. DOI: 10.46991/PYSUA.2003.37.3.025. Disponível em: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol37_no3_2003_pp025-029. Acesso em: 22 jan. 2026.