Bernard Gibert, Cubics related to coaxial circles,
Forum Geometricorum, 8 (2008) 77--95.
Abstract: This note generalizes a result of Paul Yiu on a locus associated
with a triad of coaxial circles. We present an interesting family of cubics
with many properties similar to those of pivotal cubics. It is also
an opportunity to show how different ways of writing the equation of a cubic
lead to various geometric properties of the curve.