Eisso J. Atzema, An elementary proof of a theorem by Emelyanov,
Forum Geometricorum, 8 (2008) 201--204.

Abstract: In this note, we provide an alternative proof of a theorem by Lev Emelyanov stating that the Miquel point of any complete quadrilateral (in general position) lies on the nine-point circle of the triangle formed by the diagonals of that same complete quadrilateral.

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