1. Sur le quatrième probléme et les nombres de Schröder;Comtet;C. R. Acad. Sci. Paris,,1970
2. Advanced Combinatorics;Comtet,1974
3. Enumeration of phylogenetic trees without points of degree two;Foulds;Ars Combin.,,1984
4. Limit Distribution for Sums of Independent Random Variables;Gnedenko,1968
5. Graphical Enumeration;Harary,1973