MLA
Wesley, Sarah, 1759-1828. Letter from Sarah Wesley to [Sarah (Gwynne)] Wesley, Dover, including note from Charles Wesley junior - September 8, 1803. September 8, 1803. Wesleyana Collection. Pitts Theology Library. https://digital.library.emory.edu/purl/10966t1gjx-cor.
APA, 6th edition
Wesley, Sarah, 1759-1828. (September 8, 1803)[Letter from Sarah Wesley to [Sarah (Gwynne)] Wesley, Dover, including note from Charles Wesley junior - September 8, 1803]. Wesleyana Collection, Pitts Theology Library. https://digital.library.emory.edu/purl/10966t1gjx-cor.
Chicago
Wesley, Sarah, 1759-1828, Letter from Sarah Wesley to [Sarah (Gwynne)] Wesley, Dover, including note from Charles Wesley junior - September 8, 1803, September 8, 1803, Wesleyana Collection, Pitts Theology Library. https://digital.library.emory.edu/purl/10966t1gjx-cor.