[1] Abel N. H.,: Beweis eines Ausdruckes, von welchem die Binomial-Formel ein einzelner Fall ist. J. reine und angew. Math. 1 (1826), 159-160. (Démonstration d'une expression de laquelle la formule binome est un cas particulier, Oeuvres complétes, 2-éme éd., T. 1, 1881, p. 102.)

[2] Birnbaum Z. W., Pyke R.: On some distributions related to the statistics $D^+_n$. Ann. Math. Statistics 29 (1958), 179-187. MR 0093873

[3] Hagen J. G.: Synopsis der hőheren Mathematik. Bd. I (1891), 55-68.

[4] Gould H. W., Kaucký J.: Evaluation of a class of binomial coefficient summations. J. Combinatorial Theory 1 (1966), 233-247. MR 0210607

[5] Engelberg O.: Generalizations of the ballot problem. Z. Wahrscheinlichkeitstheorie und Verw. Gebiete 3 (1965), 271-275. MR 0185626 | Zbl 0131.17304

[6] Austin T. L.: The enumeration of point labelled chromatic graphs and trees. Canad. J. Math. 12 (1960), 535-545. MR 0139544 | Zbl 0096.17802

[7] Shell D. L.: Advanced problem 4960. Amer. Math. Monthly 68 (1961), 383. MR 1531205

[8] Csőrgő M.: Exact probability distribution functions of some Rényi type statistics. Proc. Amer. Math. Soc. 16 (1965), 1159-1160. MR 0214178

[9] Riordan J.: Enumeration of linear graphs for mapping of finite sets. Ann. Math. Statistics 33 (1962), 178-185. MR 0133250

[10] Matsuoka Y.: Advanced problem 4984. Amer. Math. Monthly 68 (1961).