@article{10_4171_ifb_227,
     author = {Kazuhiro Ishige and Paolo Salani},
     title = {Convexity breaking of the free boundary for porous medium equations},
     journal = {Interfaces and free boundaries},
     pages = {75--84},
     year = {2010},
     volume = {12},
     number = {1},
     doi = {10.4171/ifb/227},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ifb/227/}
}