@article{AIHPA_1991__55_1_545_0,
     author = {Pordt, A. and Reisz, T.},
     title = {On the renormalization group iteration of a two-dimensional hierarchical non-linear $O(N) \sigma $-model},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {545--587},
     publisher = {Gauthier-Villars},
     volume = {55},
     number = {1},
     year = {1991},
     zbl = {0734.58052},
     language = {en},
     url = {http://www.numdam.org/item/AIHPA_1991__55_1_545_0/}
}