found: Pitt, W. The speech of the Right Hon. William Pitt, 1799:imprint on t.p. (George Grierson, printer to the King's most excellent Majesty)
found: Munter, R. Dict. of the print trade in Ireland 1550-1775, 1988(under Grierson, Mary: second wife of Hugh Boulter Primrose Grierson; upon the latter's death [in 1771] she continued the family business and kept in trust for their son, George, the right as King's Printer)
found: ESTC (RLIN), April 27, 1999(usage: George Grierson, Geo. Grierson, Georgius Grierson, G. Grierson; appears in imprints 1784-1800)