Clark Kimberling, Translated triangles perspective to a reference
Forum Geometricorum, 6 (2006) 269--284.
Abstract: Suppose A, B, C, D, E, F are points and L is a line other than
the line at infinity. This work examines cases in which a translation D'E'F'
of DEF in the direction of L is perspective to ABC, in the sense that
the lines AD', BE', CF' concur.