MLA

Alken, Samuel, 1756-1815, printmaker. http://id.loc.gov/authorities/names/n97864144. Bathing machines [graphic] / drawn by Rowlandson ; tinted by Alken.. 1790 June 1. https://collections.library.yale.edu/catalog/11791618.

APA, 6th edition

Alken, Samuel, 1756-1815, printmaker. http://id.loc.gov/authorities/names/n97864144. (1790 June 1)[Bathing machines [graphic] / drawn by Rowlandson ; tinted by Alken.]. https://collections.library.yale.edu/catalog/11791618.