Addendum to: Closed orbits of fixed energy for a class of N-body problems (Q1202505)

In Lemma of 6 the authors' paper [ibid. 9, No. 2, 187-200 (1992; Zbl 0757.70007)] it is claimed that critical points of \(f_ \epsilon\) are found by applying the mountain-pass theorem. Actually, such a theorem needs to be slightly changed, in order to make it applicable in Lemma 6. We indicate the required modification.