Chobanov, Georgi, and Ivan Chobanov. “LAGRANGE OR EULER? PART TWO: THE PRESENT”. Ann. Sofia Univ. Fac. Math. and Inf. 82, no. 2 (December 12, 1991): 5–62. Accessed December 5, 2024. https://stipendii.uni-sofia.bg/index.php/fmi/article/view/537.