References
- Loomis , E. S. 1968 . The Pythagorean Proposition , NCTM .
- Wallace , E. C. and West , S. F. 1998 . Roads to Geometry , second edition , Upper Saddle River : Prentice Hall .
- Greenberg , M. J. 1980 . Euclidean and Non-Euclidean Geometries , second edition , New York : W. H. Freeman and Company .