Letter The author thanks for the invitation but has to turn it down because of his already planned other commitments; he informs of his visit to GDR in October and asks is it possible to arrange a one-day visit to West Berlin during the stay Date: 08.04.1974 Original document language: English Authors: Andrei Petrovich Ershov Organizations: Berlin Technische Univer. Persons: Cornelius Koster Addressee: E. Denert
