@article{CRMATH_2006__342_8_557_0,
     author = {Kruglikov, Boris and Lychagin, Valentin},
     title = {Multi-brackets of differential operators and compatibility of {PDE} systems},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {557--561},
     publisher = {Elsevier},
     volume = {342},
     number = {8},
     year = {2006},
     doi = {10.1016/j.crma.2006.02.013},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2006.02.013/}
}