@article{DCG_1993__10_2_131285,
     author = {Jung-Heum Park and Sung Yong Shin and Kyung-Yong Chwa and T.C. Woo},
     title = {On the {Number} of {Guard} {Edges} of a {Polygon.}},
     journal = {Discrete & computational geometry},
     pages = {447--462},
     publisher = {mathdoc},
     volume = {10},
     number = {2},
     year = {1993},
     zbl = {0788.52005},
     url = {http://geodesic.mathdoc.fr/item/DCG_1993__10_2_131285/}
}