Marvin J. Greenberg. Euclidean and Non-Euclidean Geometries.W. H. Freeman and Company, 1997.
George E. Martin. The Foundations of Geometry and the Non-Euclidean Plane.Springer- Verlag New York, Inc., 1975.
Frank Ayres Jr. Trigonometria Plana e Esférica.Editora McGraw-Hill do Brasil Ltda. Coleção Schaum, 1973.