@article {IOPORT.00969102,
    author       = {Deogun, Jitender S. and Sarasamma, Suseela T.},
    title        = {On the minimum co-operative guard problem.},
    year         = {1996},
    journal      = {JCMCC. The Journal of Combinatorial Mathematics and Combinatorial Computing},
    volume       = {22},
    issn         = {0835-3026},
    pages        = {161-182},
    publisher    = {Charles Babbage Research Centre, Winnipeg},
    abstract     = {Summary: We study the minimum co-operative guards problem, a variation of the art gallery problem. First, we show that the minimum number of co-operative guards required for a $k$-spiral polygon is at most $N_k$, the total number of reflex vertices in the $k$-spiral. Then we classify 2-spirals into seven different types based on the structure. Finally, we present a minimum co-operative guard placement algorithm for general 2-spirals.},
    identifier   = {00969102},
}