UdG users
1968-01-31 Letter
[1968]-07-12 Letter
1969-12-10 Letter
1971-11-25 Letter
1972-03-24 Letter
1973-08-18 Letter
1974-08-30 Letter
1974-10-10 Letter
1982-10-18 Letter
1982-11-25 Letter
1984-01-30 Letter
1986-11-11 Letter