@article{JEMS_2007_9_4_a9,
     author = {Piero D'Ancona and Damiano Foschi and Sigmund Selberg},
     title = {Null structure and almost optimal local regularity for the {Dirac-Klein-Gordon} system},
     journal = {Journal of the European Mathematical Society},
     pages = {877--899},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {2007},
     doi = {10.4171/jems/100},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/100/}
}