1. Problem 119;de Bruijn;Mat. Lapok,1961
2. The Solution of problem 119;Hajo´;Mat. Lapok,1962
3. Graphs and matching theorems;Ore;Duke Math. J.,1955
4. Ma´trixok kombinatorikus tulajdonsa´gairo´l;Egerva´ry;Mat. Fiz. Lapok,1931
5. On Combinatorial Properties of Matrices;Kuhn;George Washington Univ. Logistic Papers,1955