1. Edge-disjoint branchings;Edmonds,1973
2. A. Frank, On disjoint trees and arborescences, in: Algebraic Methods in Graph Theory, Colloquia Mathematica Societatis Janos Bolyai, Vol. 25, North-Holland, Amsterdam, 1978, pp. 159–169.
3. Kernel systems of directed graphs;Frank;Acta Sci. Math. (Szeged),1979
4. On the orientation of graphs;Frank;J. Combin. Theory B,1980
5. Structures of polyhedra determined by submodular functions on crossing families;Fujishige;Math. Programming,1984