Koganov, L. M. On a directed graph connected with an ordered pair of ordered partitionings. (Russian) Zbl 0616.05039 Mat. Zametki 41, No. 1, 101-103 (1987). Reviewer: V.Fleischer MSC: 05C20 05A17 PDF BibTeX XML Cite \textit{L. M. Koganov}, Mat. Zametki 41, No. 1, 101--103 (1987; Zbl 0616.05039)
Vilenkin, N. Ya.; Koganov, L. M. A combinatorial proof of certain identities. (Russian) Zbl 0392.05010 Mat. Zametki 24, 295-299 (1978). MSC: 05A19 05B20 PDF BibTeX XML Cite \textit{N. Ya. Vilenkin} and \textit{L. M. Koganov}, Mat. Zametki 24, 295--299 (1978; Zbl 0392.05010)