@article{MM2_1998__95_3_156370,
     author = {U. Bunke and H. Koch},
     title = {The ...-form and a generalized {Maslov} index.},
     journal = {Manuscripta mathematica},
     pages = {189--212},
     publisher = {mathdoc},
     volume = {95},
     number = {3},
     year = {1998},
     zbl = {0920.58045},
     url = {http://geodesic.mathdoc.fr/item/MM2_1998__95_3_156370/}
}