@article{10_4064_sm_100_3_219_228,
     author = {Ferdinand Beckhoff},
     title = {Korovkin theory in normed algebras},
     journal = {Studia Mathematica},
     pages = {219--228},
     publisher = {mathdoc},
     volume = {100},
     number = {3},
     year = {1991},
     doi = {10.4064/sm-100-3-219-228},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-100-3-219-228/}
}