1. The Jacobian conjecture: Reduction of degree and formal expansion of the inverse;Bass;Bull. Amer. Math. Soc.,1982
2. Permutation statistics and linear extensions of posets;Björner;J. Combin. Theory Ser. A,1991
3. On the theory of analytical forms called trees;Cayley,1890
4. On the theory of analytical forms called trees, second part;Cayley,1891
5. A note on plane trees;de Bruijn;J. Combin. Theory,1967