Alexei Myakishev and Peter Woo, On the circumcenters of cevasix configurations,
Forum Geometricorum 3 (2003) 57--63.

Abstract:  We strengthen Floor van Lamoen's theorem that the 6 circumcenters of the cevasix configuration of the centroid of a triangle are concyclic by giving a proof which at the same time shows that the converse is also true with a minor qualification,  i.e., the circumcenters of the cevasix configuration of a point P are concyclic if and only if P is the centroid or the orthocenter of
the triangle.

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