There are 2 titles associated with this firm.

Sandham , E. (1833). Sketches of young people, or, a visit to brighton. by the author of the grandfather, friendship, the schoolfellows, &c. &c. London: Simpkin, Marshall and Co. Thomas Richardson. Samuel Horsey. Samuel Darton and Robert Harvey [1833-38]
Brown , E. (1835). Children as they are; or, tales and dialogues, for young readers from seven to twelve years of age. by the author of 'the transformation of a beech-tree.' Derby: Samuel Darton and Robert Harvey [1833-38] Thomas Richardson. Simpkin, Marshall and Co. Samuel Horsey.