The exact controllability of two nonlinear population dynamics problems is established. The first problem is age structured, and the control corresponds to a supply of individuals on a small age interval. The second one is age and space structured and the control corresponds to a supply of individuals on a small subdomain $\omega$ of the whole space domain $\Omega$. The method is based on a uniform observability result for the backward nonlocal adjoint system and on Kakutani's fixed-point theorem.
"Exact controllability of a nonlinear population-dynamics problem." Differential Integral Equations 16 (11) 1369 - 1384, 2003.