@article{Feichtinger2003,
author = {Feichtinger, G. and Tragler, G. and Veliov, V.M.},
title= {Optimality conditions for age-structured control systems},
year = {2003},
doi = {10.1016/j.jmaa.2003.07.001},
journal = {Journal of Mathematical Analysis and Applications},
volume = {288},
number = {1},
pages = {47--68},
}