Duplicate title to Diekmann, O., Gyllenberg, M., Metz, J.A.J., Nakaoka, S., & de Roos, A.M. (2010). Daphnia revisited: Local stability and bifurcation theory for physiologically structured population models explained by way of an example. Journal of Mathematical Biology 61 (2) 277-318. 10.1007/s00285-009-0299-y.