There are 3 titles associated with this firm.

@book{ wphp_12447
  author={Richardson,Caroline E.},
  year={1828},
  title={Poems, By Mrs. G. G. Richardson, Dumfries.},
  publisher={Robert Cadell and Co. [41 St. Andrew Street] \& Simpkin, Marshall and Co. \& William Crofts \& },
  address={Edinburgh},    }
@book{ wphp_12448
  author={Richardson,Caroline E.},
  year={1828},
  title={Poems, By Mrs. G. G. Richardson, Dumfries. Second edition.},
  publisher={Robert Cadell and Co. [41 St. Andrew Street] \& Simpkin, Marshall and Co. \& William Crofts \& },
  address={Edinburgh},    }
@book{ wphp_12494
  author={Richardson,Caroline E.},
  year={1834},
  title={Poems by Mrs. G. G. Richardson. Second Series.},
  publisher={Robert Cadell and Co. [31 St. Andrew Square 1830, 1833-1850] \& William Crofts \& },
  address={London},    }