@article{IM_1992__107_1_143967,
     author = {Daniel S. Freed and Richard B. Melrose},
     title = {A mod k index theorem.},
     journal = {Inventiones mathematicae},
     pages = {283--300},
     publisher = {mathdoc},
     volume = {107},
     number = {1},
     year = {1992},
     zbl = {0760.58039},
     url = {http://geodesic.mathdoc.fr/item/IM_1992__107_1_143967/}
}