TY JOUR TI Imaginary Points in Cartesian Coordinate System KW complex Cartesian coordinates KW elliptic involution KW polarity KW orthogonal circles KW bunch of circles KW circumference zero radius JO Geometry & Graphics AU Girsh, A.G. AU Korotkiy, V.A. PY 2019 IS 7 PB INFRA-M Academic Publishing LLC.