“…Using these results for the general case, one could give alternative proofs to Proposition 1 and Theorem 3 in the particular case of the homogeneous system (1). This could be done in the framework of remarkable values, see [6,12,13] and the references therein, and using the necessary conditions for the existence of invariant algebraic curves, see [7] and the references therein. In particular, in [12], there are several results about systems of the form (2) which have a Darboux first integral characterizing the existence of a polynomial inverse integrating factor.…”