@article{AM2_1977__16_136687,
     author = {Marek Cezary Zdun},
     title = {On the iteration of the hat-functions.},
     journal = {Aequationes mathematicae},
     pages = {181--182},
     publisher = {mathdoc},
     volume = {16},
     year = {1977},
     zbl = {0424.26002},
     url = {http://geodesic.mathdoc.fr/item/AM2_1977__16_136687/}
}