@article{10_4064_sm183_2_2,
     author = {Vugar E. Ismailov},
     title = {On the approximation by compositions of fixed
multivariate functions with univariate functions},
     journal = {Studia Mathematica},
     pages = {117--126},
     year = {2007},
     volume = {183},
     number = {2},
     doi = {10.4064/sm183-2-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm183-2-2/}
}