@article{10_4064_cm_65_1_61_64,
     author = {David Grow and Matt Insall},
     title = {An extremal set of uniqueness?},
     journal = {Colloquium Mathematicum},
     pages = {61--64},
     publisher = {mathdoc},
     volume = {65},
     number = {1},
     year = {1993},
     doi = {10.4064/cm-65-1-61-64},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-65-1-61-64/}
}