MLA

Chmielewski, Witold, 1949-, artist. Stopień ryzyka [graphic]. [1970]. https://collections.library.yale.edu/catalog/16049056.

APA, 6th edition

Chmielewski, Witold, 1949-, artist. ([1970])[Stopień ryzyka [graphic]]. https://collections.library.yale.edu/catalog/16049056.