Elements of plane and spherical trigonometry : written originally in Russian, and translated into English by the authors, Basil Nikitin, M.A. Inspector, and Prochor Souvoroff, M.A. Vice-Inspector, of the Imperial Academy of Cadets at Cronstadt. - Nikitin, Vasiliĭ Nikitich, (printed for the authors and sold by Mr. Fletcher, Oxford; Messrs. Merril, Cambridge; and Messrs. Elmsley, Strand,, 1786)