UdG users
1958-02-03 Letter
1958-11-11 Letter
1958-12-23 Letter
1959-03-01 Letter
1959-09-29 Letter
1959-11-29 Letter
1960-05-28 Letter
1961-05-07 Letter
1961-05-21 Letter
1961-06-02 Letter
1972-07-24 Letter
1975-07-15 Letter
1976-03-25 Letter
1979-08-04 Letter
[1975]-11-12 Letter
[1975]-11-24 Letter
s.d. Letter