@article{PORMA_2004__61_3_52320,
     author = {Monterde, J.},
     title = {A new proof of the existence of hierarchies of {Poisson-Nijenhuis} structures.},
     journal = {Portugaliae mathematica},
     pages = {355--368},
     publisher = {mathdoc},
     volume = {61},
     number = {3},
     year = {2004},
     zbl = {1086.53098},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_2004__61_3_52320/}
}