@article{NSJOM_1990_20_2a_12,
     author = {Fisher Brian},
     title = {On power of heaviside's 

 function},
     journal = {Novi Sad Journal of Mathematics},
     pages = {109-112},
     publisher = {mathdoc},
     volume = {20},
     number = {2},
     year = {1990},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1990_20_2a_12/}
}