Sigl, Rudolf: Continental networks. report on the activities of the IAG-Commission X; presented to the International Association of Geodesy on the occasion of the IUGG General Assembly December 2 - 15, 1979, Canberra/Australia. Beck München 1979DGK: Veröffentlichungen B: Angewandte Geodäsie: Reihe B, Angewandte Geodäsie ; 243. ISBN 3-7696-8536-9