@article{ASUO_2020_XXVIII_3_a18,
     author = {Fuat Usta~
							},
     title = {Approximation of {Functions} by {New} {Classes} of {Linear} {Positive} {Operators
}								which {Fix} $\{1,\pi\}$ and $\{1,\pi^2\}$},
     journal = {Analele Universit\u{a}\c{t}ii "Ovidius" Constan\c{t}a Seria Matematic\u{a}},
     publisher = {mathdoc},
     volume = {XXVIII},
     number = {3},
     year = {2020},
     url = {http://geodesic.mathdoc.fr/item/ASUO_2020_XXVIII_3_a18/}
}