Potrykus, A., & Jacob, N. (2007). Approximating a Feller Semigroup by Using the Yosida Approximation of the Symbol of its Generator. Positivity, 11(1), pp. 1-13. doi:10.1007/s11117-006-0053-2

Potrykus, Alexander, and Niels Jacob. "Approximating a Feller Semigroup By Using the Yosida Approximation of the Symbol of Its Generator." Positivity 11, no. 1 (2007): 1-13.

Potrykus, Alexander, and Niels Jacob. "Approximating a Feller Semigroup By Using the Yosida Approximation of the Symbol of Its Generator." Positivity 11.1 (2007): 1-13.