MLA

Knutsson, Bengt, d. 1462. Regimen contra pestilentiam. about 1486].. https://collections.library.yale.edu/catalog/16986892.

APA, 6th edition

Knutsson, Bengt, d. 1462. (about 1486].)[Regimen contra pestilentiam]. https://collections.library.yale.edu/catalog/16986892.