UdG users
1960-05-19 Letter
1960-06-08 Letter
1961-01-14 Letter
1961-04-04 Letter
1961-04-11 Letter
1962-06-07 Letter
1962-12-15 Letter
1964-04-30 Letter
1968-09-28 Letter
1968-10-07 Letter
1969-03-08 Letter
1969-04-22 Letter
1974-07-14 Letter
1974-07-30 Letter
1974-09-11 Letter
1975-02-25 Letter
1975-08-21 Letter
1975-10-14 Letter
1975-10-21 Letter
1975-11-28 Letter
1976-01-10 Letter
1976-03-05 Letter
1976-04-21 Letter
1976-06-02 Letter