@article{10_4064_sm180_1_5,
     author = {Marco Annoni and Emanuele Casini},
     title = {An upper bound for the {Lipschitz} retraction constant in $l_1$},
     journal = {Studia Mathematica},
     pages = {73--76},
     publisher = {mathdoc},
     volume = {180},
     number = {1},
     year = {2007},
     doi = {10.4064/sm180-1-5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm180-1-5/}
}