UdG users
1977-10-09 Letter
1977-11-21 Letter
1978-01-01 Letter
1978-04-20 Letter
1980-03-20 Letter
1980-03-31 Letter
1980-10-11 Letter
1980-10-25 Letter
1980-12-27 Letter
1981-03-02 Letter
1981-08-05 Letter
1981-08-17 Letter
1981-09-06 Letter
1981-10-25 Letter
1981-11-15 Letter
1981-11-25 Letter
1981-12-03 Letter
1981-12-24 Letter
1981-12-26 Letter
1982-01-31 Letter
1982-02-25 Letter
1982-04-11 Letter
1982-07-12 Letter
1982-09-16 Letter