MLA
Cownley, Joseph, 1723-1792. Letter from Joseph Cownley to Charles Wesley [Newcastle upon Tyne] - July 22, 1779. July 22, 1779. Wesleyana Collection. Pitts Theology Library. https://digital.library.emory.edu/purl/8708w9gjgm-cor.
APA, 6th edition
Cownley, Joseph, 1723-1792. (July 22, 1779)[Letter from Joseph Cownley to Charles Wesley [Newcastle upon Tyne] - July 22, 1779]. Wesleyana Collection, Pitts Theology Library. https://digital.library.emory.edu/purl/8708w9gjgm-cor.
Chicago
Cownley, Joseph, 1723-1792, Letter from Joseph Cownley to Charles Wesley [Newcastle upon Tyne] - July 22, 1779, July 22, 1779, Wesleyana Collection, Pitts Theology Library. https://digital.library.emory.edu/purl/8708w9gjgm-cor.