@article{10_21136_CPM_1978_117971,
     author = {M\v{e}ska, Ji\v{r}{\'\i}},
     title = {Expressing $f\in\cal D$ as a difference of two positive functions $f_1,f_2\in \cal D$},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {62--66},
     year = {1978},
     volume = {103},
     number = {1},
     doi = {10.21136/CPM.1978.117971},
     mrnumber = {0492141},
     zbl = {0374.26015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1978.117971/}
}