Chobanov, G., and I. Chobanov. “Newtonian and Eulerian Dynamical Axioms. V. Prehistory of Mechanical Constraints”. Ann. Sofia Univ. Fac. Math. And Inf., vol. 86, no. 2, Dec. 1994, pp. 73-98, https://ftl5.uni-sofia.bg./index.php/fmi/article/view/507.