There are 3 titles associated with this firm.

@book{ wphp_14619
  author={Douglas,Mary and Douglas,Andrew},
  year={1797},
  title={Notes of a Journey from Berne to England, through France. Made in the Year 1796. By A. D.},
  publisher={},
  address={London},    }
@book{ wphp_10803
  author={Pilkington,Mary},
  year={1802},
  title={Marvellous adventures, or, The vicissitudes of a cat: in which are sketches of the characters of the different young ladies and gentlemen into whose hands Grimalkin came. By Mrs. Pilkington.},
  publisher={Ann Vernor and Thomas Hood [Poultry] \& John Harris [1802-1819, 1824-1843] \& },
  address={London},    }
@book{ wphp_11289
  author={Williams,Helen Maria},
  year={1803},
  title={Poems, Moral, Elegant and Pathetic: viz. Essay on Man, by Pope; the Monk of La Trappe, by Jerningham; the Grave, by Blair; An Elegy in a Country Churchyard, by Gray; the Hermit of Wark-Worth, by Percy; and Original Sonnets, by Helen Maria Williams.},
  publisher={John Harris [1802-1819, 1824-1843] \& Ann Vernor and Thomas Hood [Poultry] \& },
  address={London},    }