@article {GreifLiSchotzauWei2010,
    AUTHOR = {Greif, Chen and Li, Dan and Sch{\"o}tzau, Dominik and Wei,
              Xiaoxi},
     TITLE = {A mixed finite element method with exactly divergence-free
              velocities for incompressible magnetohydrodynamics},
   JOURNAL = {Comput. Methods Appl. Mech. Engrg.},
    VOLUME = {199},
      YEAR = {2010},
    NUMBER = {45-48},
     PAGES = {2840--2855}
}