1. Integral distances;Anning, Norman H.;Bull. Amer. Math. Soc.,1945
2. Rational polygons;Besicovitch, A. S.;Mathematika,1959
3. Rational polygons;Daykin, D. E.;Mathematika,1963
4. Integral distances;Erdös, Paul;Bull. Amer. Math. Soc.,1945
5. Problem Books in Mathematics;Guy, Richard K.,1981