Letter The addressee is invited to make a report at the Fourth All-union Conference on Computer Graphics Problems, which will be held in 1987, September 9 - 11, in Protvino. /Handwritten note by Andrei Petrovich: "Orally at the beginning of July - I can't"/ Date: 10.06.1987(?) Original document language: Russian Authors: Stanislav V. Klimenko Addressee: Andrei Petrovich Ershov
