Aubin, J.-P. <https://pure.iiasa.ac.at/view/iiasa/1134.html>, Frankowska, H., & Olech, C.  (1986).  Controllability of Convex Processes.   SIAM Journal on Control and Optimization 24 (6) 1192-1211. 10.1137/0324072 <https://doi.org/10.1137/0324072>.