Kells, Kern. Plane and spherical trigonometry. In English /Kells,Kern. Plane and spherical trigonometry. Kells, Kern. Plane and spherical trigonometry. 1940. We have thousands of titles and often several copies of each title may be available. Please feel free to contact us for a detailed description of the copies available. SKUalb6b3e89307715f314.