@article{CRMATH_2010__348_21-22_1217_0,
     author = {Burman, Erik},
     title = {Ghost penalty},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {1217--1220},
     publisher = {Elsevier},
     volume = {348},
     number = {21-22},
     year = {2010},
     doi = {10.1016/j.crma.2010.10.006},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2010.10.006/}
}