MLA

Mess. Kellys, Whip and Umbrella-Makers to the Prince of Wales and Princess Royal, The King's Arms, No. 139, near Somerset House, Strand, London. Mess. Kellys, 0AD. https://collections.library.yale.edu/catalog/15812333.

APA, 6th edition

Mess. Kellys, whip and umbrella-makers to the Prince of Wales and Princess Royal, The King's Arms, No. 139, near Somerset House, Strand, London. (0 C.E.). [Woodcuts England 1790, Annotations (Provenance), Advertisements]. Mess. Kellys. https://collections.library.yale.edu/catalog/15812333.