@article{RSMUP_1976__55__45_0,
     author = {Malik, M. A.},
     title = {An approximation property for abstract differential equations},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {45--48},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {55},
     year = {1976},
     mrnumber = {508657},
     zbl = {0376.34047},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_1976__55__45_0/}
}