@article{EUG_1990_26_a2,
     author = {E. M. Giannacoulias},
     title = {Compositions of operators with vector valued maps},
     journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\Gamma}},
     pages = {41--45},
     year = {1990},
     volume = {26},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/EUG_1990_26_a2/}
}