Astronomy explained upon Sir Isaac Newton's principles : and made easy to those who have not studied mathematics. To which are added, a plain method of finding the distances of all the planets from the sun, ... By James Ferguson. - Ferguson, James (printed for J. F. and C. Rivington, T. Longman, B. Law, J. Johnson, G. G. J. and J. Robinson, [and 7 others in London], 1790)