@article{MZ_1988__200_3_174018,
     author = {Jaroslaw A. Wisniewski},
     title = {Length of {Extremal} {Rays} and {Generalized} {Adjunction.}},
     journal = {Mathematische Zeitschrift},
     pages = {409--428},
     year = {1988},
     volume = {200},
     number = {3},
     zbl = {0668.14004},
     url = {http://geodesic.mathdoc.fr/item/MZ_1988__200_3_174018/}
}