UdG users
1966-09-05 Letter
1966-11-08 Letter
1966-11-15 Letter
1967-02-16 Letter
1967-03-27 Letter
1968-06-22 Letter
1969-05-20 Letter
1970-03-10 Letter
1970-04-04 Letter
1971-03-29 Letter
1971-04-16 Letter
1971-06-13 Letter
1973-12-10 Letter
1975-08-05 Letter
1975-08-06 Letter
1975-12-24 Letter
1977-01-19 Letter
1977-09-23 Letter
1978-04-02 Letter
1979-04-22 Letter
1980-06-23 Letter
1982-03-17 Letter