Üna schoppa per Zipf ün'istorgia in puter e vallader Daniel Badraun ; illustraziuns da Daniela Räss ; traducziun in puter: Chatrina Urech-Clavuot, in vallader: Mario Pult
Bibliothekskatalog der Kantonsbibliothek Graubünden: https://www.opac.gr.ch/discovery/fulldisplay?context=L&vid=41BGR_INST:41BGR_V1&search_scope=MyInstitution&tab=LibraryCatalog&docid=alma990006928410206696