@article{TM2_1998_I_1_a3,
     author = {Vladimir Jankovi\'c},
     title = {Improper {Integral}},
     journal = {The Teaching of Mathematics},
     pages = {53 },
     publisher = {mathdoc},
     volume = {I},
     number = {1},
     year = {1998},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TM2_1998_I_1_a3/}
}