UdG users
1948-02-21 Letter
1950-04-20 Letter
1951-05-19 Letter
1951-08-07 Letter
1951-08-14 Letter
1951-10-11 Letter
1952-01-28 Letter
1952-05-25 Letter
1953-12-03 Letter
1956-01-09 Letter
1956-05-05 Letter
1956-08-22 Letter
1957-02-09 Letter
1957-03-21 Letter
1959-09-02 Letter