UdG users
1954-12-05 Letter
1956-09-14 Letter
1956-12-09 Letter
1957-07-04 Letter
1957-11-29 Letter
1958-10-19 Letter
1959-12-24 Letter
1960-05-21 Letter
1961-01-23 Letter
1962-08-06 Letter
1964-09-06 Letter
1964-12-17 Letter
1968-04-30 Letter
1973-07-02 Letter