MLA

Hopkins, Samuel, 1721-1803. A dialogue, concerning the slavery of the Africans : shewing it to be the duty and interest of the American colonies to emancipate all their African slaves: with an address to the owners of such slaves : dedicated to the honorable the Continental congress. 1776.. https://collections.library.yale.edu/catalog/33066124.

APA, 6th edition

Hopkins, Samuel, 1721-1803. (1776.)[A dialogue, concerning the slavery of the Africans : shewing it to be the duty and interest of the American colonies to emancipate all their African slaves: with an address to the owners of such slaves : dedicated to the honorable the Continental congress]. https://collections.library.yale.edu/catalog/33066124.