A proof of Waring's Expression for Σar in terms of the Coefficients of an Equation
R. F. Muirhead · Proceedings of the Edinburgh Mathematical Society · 1904
While Newton's Theorem on the Sums of Powers of the Roots of an equation furnishes a set of lineo-linear equations connecting the quantities s1, s2, s3, … and the quantities p1, p2, p3, … Waring gives the solution of these equations by which the s's are expressed in terms of the p's.