@article{CRMATH_2005__340_9_639_0,
     author = {Alpay, Daniel and Luna-Elizarrar\'as, Maria-Elena and Shapiro, Michael},
     title = {Normes des extensions quaternionique d'op\'erateurs r\'eels},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {639--643},
     publisher = {Elsevier},
     volume = {340},
     number = {9},
     year = {2005},
     doi = {10.1016/j.crma.2005.03.030},
     language = {fr},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2005.03.030/}
}