There are 5 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_15364
  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. \& John Sinclair},
  address={Edinburgh},    }
@book{ wphp_9385
  author={Corbett,Marion and Corbett,Margaret},
  year={1828},
  title={Tales and Legends. By the authors of "The Odd Volume," &c. In three volumes.},
  publisher={W. Simpkin and R. Marshall \& Robert Cadell and Co. [41 St. Andrew Street] \& },
  address={Edinburgh},    }
@book{ wphp_12406
  author={Richardson,Caroline E.},
  year={1829},
  title={Poems. By Mrs. G. G. Richardson, Dumfries.},
  publisher={Robert Cadell and Co. [41 St. Andrew Street] \& Simpkin, Marshall and Co. \& John Sinclair},
  address={Edinburgh},    }