@article{PNA_2009_2009_1_a3,
     author = {Ortiz, Alfonso},
     title = {L\'ogica y {Pensamiento} {Aritm\'etico.}},
     journal = {PNA},
     pages = {51-72},
     publisher = {mathdoc},
     volume = {3},
     number = {2},
     year = {2009},
     language = {es},
     url = {http://geodesic.mathdoc.fr/item/PNA_2009_2009_1_a3/}
}