@article{TM2_2019_XXII_1_a0,
     author = {Milosav M. Marjanovi\'c and Zoran Kadelburg},
     title = {Structuring systems of natural, positive rational, and rational numbers},
     journal = {The Teaching of Mathematics},
     pages = {1 },
     publisher = {mathdoc},
     volume = {XXII},
     number = {1},
     year = {2019},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TM2_2019_XXII_1_a0/}
}