Salma Sadat Mahdavi Saeed Seddighin Mohammad Ghodsi Covering Orthogonal Polygons with Sliding k-Transmitters. 2014 CCCG http://www.cccg.ca/proceedings/2014/papers/paper12.pdf conf/cccg/2014 db/conf/cccg/cccg2014.html#MahdaviSG14