There are 2 titles associated with this firm.

Richardson , C.E. (1828). Poems. by mrs. g. g. richardson, dumfries. Edinburgh: Robert Cadell and Co. [41 St. Andrew Street] Simpkin, Marshall and Co. John Sinclair.
Richardson , C.E. (1829). Poems. by mrs. g. g. richardson, dumfries. Edinburgh: Robert Cadell and Co. [41 St. Andrew Street] Simpkin, Marshall and Co. John Sinclair.