@article{JFAA_2000__6_1_59631,
     author = {Vladimir Protasov},
     title = {Refinement {Equations} with {Nonnegative} {Coefficients.}},
     journal = {The journal of Fourier analysis and applications},
     pages = {55--78},
     year = {2000},
     volume = {6},
     number = {1},
     zbl = {0974.42023},
     url = {http://geodesic.mathdoc.fr/item/JFAA_2000__6_1_59631/}
}