Model-based strategy for cell culture seed train layout verified at lab scale
S. Kern, O. Platas-Barradas, R. Pörtner, B. Frahm, Cytotechnology 68 (2015) 1019–1032.

Improving bioreactor cultivation conditions for sensitive cell lines by dynamic membrane aeration
B. Frahm, H. Brod, U. Langer, Cytotechnology 59 (2009) 17–30.