Altomare, Francesco and Campiti, Michele. "Chapter 3 Korovkin-type theorems for positive linear operators".
Korovkin-type Approximation Theory and Its Applications, Berlin, New York: De Gruyter, 2011, pp. 141-194.
https://doi.org/10.1515/9783110884586.141Altomare, F. & Campiti, M. (2011). Chapter 3 Korovkin-type theorems for positive linear operators. In
Korovkin-type Approximation Theory and Its Applications (pp. 141-194). Berlin, New York: De Gruyter.
https://doi.org/10.1515/9783110884586.141Altomare, F. and Campiti, M. 2011. Chapter 3 Korovkin-type theorems for positive linear operators.
Korovkin-type Approximation Theory and Its Applications. Berlin, New York: De Gruyter, pp. 141-194.
https://doi.org/10.1515/9783110884586.141Altomare, Francesco and Campiti, Michele. "Chapter 3 Korovkin-type theorems for positive linear operators" In
Korovkin-type Approximation Theory and Its Applications, 141-194. Berlin, New York: De Gruyter, 2011.
https://doi.org/10.1515/9783110884586.141Altomare F, Campiti M. Chapter 3 Korovkin-type theorems for positive linear operators. In:
Korovkin-type Approximation Theory and Its Applications. Berlin, New York: De Gruyter; 2011. p.141-194.
https://doi.org/10.1515/9783110884586.141