MLA
Wesley, John, 1703-1791. Letter from John Wesley to "Sister" Gobby, Haverford - August 12, 1790. August 12, 1790. Wesleyana Collection. Pitts Theology Library. https://digital.library.emory.edu/purl/675r7sqvtt-cor.
APA, 6th edition
Wesley, John, 1703-1791. (August 12, 1790)[Letter from John Wesley to "Sister" Gobby, Haverford - August 12, 1790]. Wesleyana Collection, Pitts Theology Library. https://digital.library.emory.edu/purl/675r7sqvtt-cor.
Chicago
Wesley, John, 1703-1791, Letter from John Wesley to "Sister" Gobby, Haverford - August 12, 1790, August 12, 1790, Wesleyana Collection, Pitts Theology Library. https://digital.library.emory.edu/purl/675r7sqvtt-cor.