@article{KJM_2003_25_1_a7,
     author = {Verica Milutinovi\'c},
     title = {An algorithm for calculation of (+, *) - expressions with natural numbers},
     journal = {Kragujevac Journal of Mathematics},
     pages = {81 - 90},
     publisher = {mathdoc},
     volume = {25},
     number = {1},
     year = {2003},
     zbl = {1080.68114},
     url = {http://geodesic.mathdoc.fr/item/KJM_2003_25_1_a7/}
}