Laurence Puel. Using Unavoidable Set of Trees to Generalize Kruskal s Theorem. Journal of Symbolic Computation, 8(4):335-382, 1989.
@article{Puel89, title = {Using Unavoidable Set of Trees to Generalize Kruskal s Theorem}, author = {Laurence Puel}, year = {1989}, researchr = {https://researchr.org/publication/Puel89}, cites = {0}, citedby = {0}, journal = {Journal of Symbolic Computation}, volume = {8}, number = {4}, pages = {335-382}, }