@article{SIGMA_2009_5_a22,
     author = {Wei Khim Ng and Rajesh R. Parwani},
     title = {Nonlinear {Dirac} {Equations}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2009},
     volume = {5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2009_5_a22/}
}