@article{10_4064_sm_33_2_175_183,
     author = {Gra\.zyna Toporowska},
     title = {The minimal norm problem and {Pontriagin's} maximum principle for {Banach} spaces {(I)}},
     journal = {Studia Mathematica},
     pages = {175--183},
     year = {1969},
     volume = {33},
     number = {2},
     doi = {10.4064/sm-33-2-175-183},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-33-2-175-183/}
}