@inProceedings{PolicellaEtAlIWPSS09,
    author =    {Policella, Nicola and Oliveira, Henrique and Siili, Tero},
    title =     {Managing {SOHO}'s Keyhole Periods: Problem Definition and Solving Model},
    booktitle = {Proceedings of the 6$^{th}$ International Workshop on Planning and Scheduling for Space, IWPSS-09},
    year = 2009
}