@article{10_4171_ifb_118,
     author = {Shangbin Cui},
     title = {Global existence of solutions for a free boundary problem modeling the growth of necrotic tumors},
     journal = {Interfaces and free boundaries},
     pages = {147--159},
     year = {2005},
     volume = {7},
     number = {2},
     doi = {10.4171/ifb/118},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ifb/118/}
}