@article{10_4171_ifb_147,
     author = {John W. Barrett and Leonid Prigozhin},
     title = {Dual formulations in critical state problems},
     journal = {Interfaces and free boundaries},
     pages = {349--370},
     year = {2006},
     volume = {8},
     number = {3},
     doi = {10.4171/ifb/147},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ifb/147/}
}