Copy an open letter (hand-written) to Prof. Honsberger with the proof of Morley's theorem (with the note to A.Ershov from the author) Date: 30.12.1975 Original document language: English Authors: Edsger W. Dijkstra Organizations: Univer. of Waterloo Addressee: Andrei Petrovich Ershov, Ross Honsberger