MLA

Rowlandson, Thomas, 1756-1827. Letter : to Henry Angelo, 1815 July 18.. Vol. 1 (Box 1 of 2) | Folder I - preface letter. 1815 July 18. https://collections.library.yale.edu/catalog/11791294.

APA, 6th edition

Rowlandson, Thomas, 1756-1827. (["Vol. 1 (Box 1 of 2) | Folder I - preface letter"])(1815 July 18)[Letter : to Henry Angelo, 1815 July 18.]. https://collections.library.yale.edu/catalog/11791294.