@article{10_4064_cm112_2_4,
     author = {Bekkai Messirdi and Mohammed Hichem Mortad and Abdelhalim Azzouz and Ghouti Djellouli},
     title = {A topological characterization of the
 product of two closed operators},
     journal = {Colloquium Mathematicum},
     pages = {269--278},
     publisher = {mathdoc},
     volume = {112},
     number = {2},
     year = {2008},
     doi = {10.4064/cm112-2-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm112-2-4/}
}