[1] A. Aeppli: Zur Theorie Verketteter Wahrscheinlichkeiten. Thèse, Zürich (1924).
[2] D. André: Solution directe du problème rèsolu par M. Bertrand. C. R. Acad. Sci. (Paris), 105 (1887), 436-437.
[3] É. Barbier: Généralisation du problème rèsolu par M. J. Bertrand. C. R. Acad. Sci. (Paris), 105 (1887), 407.
[4] J. Bertrand: Solution ďun probléme. C. R. Acad. Sci. (Paris), 105 (1887), 369.
[5] M. T. L. Bizley: 
Derivation of a new formula for the number of minimal lattice paths from $(0, 0)$ to $(km, kn)$ having just t contacts with the line $my = nx$ and having no points above this line; and a proof of Grossman's formula for the number of paths which may touch but do not rise above this line. J. Inst. Actuar., 80 (1954), 55-62. 
DOI 10.1017/S002026810005424X | 
MR 0061567[6] M. T. L. Bizley: Problem 5503. Amer. Math. Monthly, 74 (1967), 728.
[11] W. Feller: 
An introduction to probability theory and its Applications. Vol. I., Third Edition, John Wiley, New York (1968). 
MR 0228020 | 
Zbl 0155.23101[12] H. D. Grossman: Another extension of the ballot problem. Scripta Math., 16 (1950), 120-124.
[13] S. G. Mohanty T.  V. Narayana: 
Some properties of compositions and their application to probability and statistics I. Biometrische Zeitschrift, 3 (1961), 252-258. 
DOI 10.1002/bimj.19610030403[14] L. Takács: 
A generalization of the ballot problem and its application in the theory of queues. J. Amer. Statist. Assoc., 57 (1962), 327-337. 
MR 0138139[18] L.  Takács: 
Combinatorial methods in the theory of stochastic processes. John Wiley, New York (1967). 
MR 0217858