There are 2 titles associated with this firm.

@book{ wphp_2016
  author={Mackenzie,Anna Maria},
  year={1792},
  title={Slavery: or, the times. In two volumes. By the author of Monmouth, The Danish massacre, &c. ...},
  publisher={George, George, John and James Robinson \& John Dennis [Holborn]},
  address={London},    }
@book{ wphp_12513
  author={Clarke,Richard},
  year={1794},
  title={A collection of poems and letters. Poems, &c. 1. An Ode from Sans Souci, characteristic of the late Northern Potentaete, with Annotations by Machiavel in the Shades. 2. Lines on the death of Infants, &c. 3. A Father's Soliloquy over a Sleeping Child, before his going to Prison. 4. Verses on the Death of a Son four Years old. 5. On the late Fast for National Sins, &c. 6. On the French Standards hung up at St. Paul's. Letters. 1. On German Electors and Princes Hiring out their Subjects for Soldiers. 2. An Account and Defence of the Author's Publications in Support of Universal Redemption, and of his Objections to an exclusive Priesthood. 3. A short View of the Signs of Times, drawn from a larger Work on the Numbers in the Law, the Prophets, and the Gospel. 4. A Letter on the Military Profession to a Gentleman, who, from Doubt and Fear of its being inconsistent with his Christian Profession, resigned his Commission. 5. A Letter on the present Rage for Fragments of Prophecies, not founded},
  publisher={},
  address={London},    }