Simplest Singular Points of 1-forms Invariant with Respect to an Action of Group of Order Three / *F. I. Mamedova.* // Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2018. № 5. P. 60-63
[Moscow Univ. Math. Bulletin. Vol. 72, N 2, 2017. P. 199-202].

Singular points that cannot be removed by small deformations of 1-forms and
invariant with respect to the action of a cyclic group of order 3 are classified.
It is proved that for

*Key words*:
1-forms, group actions, equivariant deformations.