@article{10_4064_cm115_1_11,
     author = {Daniel Reem and Simeon Reich},
     title = {Zone and double zone diagrams in
 abstract spaces},
     journal = {Colloquium Mathematicum},
     pages = {129--145},
     publisher = {mathdoc},
     volume = {115},
     number = {1},
     year = {2009},
     doi = {10.4064/cm115-1-11},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm115-1-11/}
}