1. On sharply edge-transitive permutation groups;Babai;J. Algebra,1981
2. On matroids, groups and exchange languages;Björner,1982
3. On permutation geometries;Cameron;J. London Math. Soc.,1979
4. P. J. Cameron, M. Deza, and P. Frankl, On permutation geometries II: Blowing up, in preparation.