UdG users
1949-12-10 Letter
1951-09-20 Letter
1953-07-26 Letter
1953-12-13 Letter
1954-10-01 Letter
1956-03-05 Letter
1956-07-15 Letter
1958-01-05 Letter
1958-09-16 Letter
1959-02-03 Letter
1965-04-03 Letter
1965-04-09 Letter
1965-04-17 Letter
1965-05-23 Letter
1966-01-10 Letter
1967-08-28 Letter
1967-12-18 Letter
1968-03-02 Letter
1970-11-24 Letter