@article{MZ_1967__100_170817,
     author = {R. Askey and R.P. jr. Boas},
     title = {Fourier {Coefficients} of {Positive} {Functions.}},
     journal = {Mathematische Zeitschrift},
     pages = {373--379},
     year = {1967},
     volume = {100},
     zbl = {0175.06303},
     url = {http://geodesic.mathdoc.fr/item/MZ_1967__100_170817/}
}