1. Bollobás, B.: Ket fuggelten kort nem tartalmazo grafokrol, Mat. Lapok14, 311–321 (1963)
2. Bollobás, B.: Extremal Graph Theory, Academic Press, New York (1978)
3. Dutton, R.D. and Brigham, R.C.: Edges in graphs with large girth, Department of Mathematics Technical Report M-11, University of Central Florida, Orlando, FL 32816, 1988
4. Elsner, T.E.: Problem 6159, American Math. Monthly (1977)
5. Reiman, I.: über ein Problem von K. Zarankiewicz, Acta., Math. Acad. Sci. Hungar.9, 269–273 (1958)