His This day is published, by J. Sewell, no. 32, Cornhill, The European magazine, 1798.
Maxted, I. The London book trades 1775-1800, 1977 (Sewell, John, bookseller, 32 Cornhill; d. 1802 age 68)
Plomer, H.R. Dict. of the printers and booksellers 1726-1775, 1932: p. 36 (John Sewell went into partnership with James Brotherton ca. 1770 and succeeded to business when Brotherton died or retired in 1775)