After reviewing the existing proccdures for solving the three-body problem by convergent power series, theauthor develops two algebraic methods in terms of the independent variable which is either the time 1 or LEVI-CIVITA'S regularizing variable a.Thesc power series solve in\VEIERSTRASS' and PAINLEV~'S sense the problem formulated in itsgreatest generality, since no restrictions at all are made on the order of magnitude of masses and none of the three bodies is restricted to moving along a prescribed conic section. Rcsides, the reference system used is a tridimensional Cartesian one. I n the i-domain, the expressions for the high-order derivatives of the coordinates are computed using repeatedly LEIBNITZ'S rule for derivatives of products of functions. In the u-domain, a n extremely simple successive'approximation procedure is establishcd b y ineans ot a singlr recursion formula which requires elementary opcrations t o bc performed on polynomials of increasing degrees.