@misc{RCM_2008_42_2_a5,
     title = {Chandrasekhar ansatz and the generalized total angular momentum operator for the {Dirac} equation in the {Kerr-Newman} metric},
     journal = {Revista colombiana de matematicas},
     pages = {183--207},
     year = {2008},
     volume = {42},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/RCM_2008_42_2_a5/}
}