@article{PORMA_1990__47_2_115714,
     author = {Sierksma, Gerard and Dietzenbacher, Erik},
     title = {Starshapedness and its applications to input-output models},
     journal = {Portugaliae mathematica},
     pages = {215--226},
     publisher = {mathdoc},
     volume = {47},
     number = {2},
     year = {1990},
     mrnumber = {1090072},
     zbl = {0722.90018},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1990__47_2_115714/}
}