MLA

Regiomontanus, Joannes, 1436-1476, author, printer. Kalender. [1474]. https://collections.library.yale.edu/catalog/33567323.

APA, 6th edition

Regiomontanus, Joannes, 1436-1476, author, printer. ([1474])[Kalender]. https://collections.library.yale.edu/catalog/33567323.