Original: See also Elliptic geometry Gyrovector space Hyperbolic structure Hyperboloid structure Hjelmslev transformation Hyperbolic 3-manifold Kleinian group Poincaré metric Khayyam -- Saccheri quadrilateral Spherical geometry Systolic geometry Notes References Coxeter , H. S. M. ( 1942 ) Non-Euclidean geometry , University of Toronto Press , Toronto Milnor , John W. ( 1982 ) Hyperbolic geometry : The first 150 years , Bull .
Simplified: References Literature Coxeter , H. S. M. ( 1942 ) Non-Euclidean geometry , University of Toronto Press , Toronto Milnor , John W. ( 1982 ) Hyperbolic geometry : The first 150 years , Bull .