Sommerville, D.M.Y.
The elements of non-euclidean geometry/ by D.M.Y. Sommerville. - New York: Dover c1958. - xvi, 274 p. : ill. ; 20 cm.
Includes index.
516.9 / S697
The elements of non-euclidean geometry/ by D.M.Y. Sommerville. - New York: Dover c1958. - xvi, 274 p. : ill. ; 20 cm.
Includes index.
516.9 / S697