@article{MM2_1998__95_3_156392,
     author = {Andreas Knauf},
     title = {The size of the shadow boundary pojection.},
     journal = {Manuscripta mathematica},
     pages = {519--528},
     publisher = {mathdoc},
     volume = {95},
     number = {3},
     year = {1998},
     zbl = {0915.53004},
     url = {http://geodesic.mathdoc.fr/item/MM2_1998__95_3_156392/}
}