Buan-nasc
https://psb.vufindnet.de/psb/Record/a0054755+03b%20:%20R%C2%81ckblicke%20-%20Ausblicke%20;%20Druckgrafik%201910%20-1930%20;%20Handschriften%20und%20Briefe%201899%20-%201936
https://psb.vufindnet.de/psb/Record/a0054755+03b%20:%20R%C2%81ckblicke%20-%20Ausblicke%20;%20Druckgrafik%201910%20-1930%20;%20Handschriften%20und%20Briefe%201899%20-%201936