{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,7]],"date-time":"2026-03-07T14:16:53Z","timestamp":1772893013486,"version":"3.50.1"},"reference-count":3,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2006,11,13]],"date-time":"2006-11-13T00:00:00Z","timestamp":1163376000000},"content-version":"vor","delay-in-days":4334,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Mathematical Logic Qtrly"],"published-print":{"date-parts":[[1995,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>D. T. Lee and A. K. Lin [2] proved that VERTEX\u2010GUARDING and POINT\u2010GUARDING are NP\u2010hard for simple polygons. We prove that those problems are NP\u2010hard for ortho\u2010polygons, too.<\/jats:p>","DOI":"10.1002\/malq.19950410212","type":"journal-article","created":{"date-parts":[[2007,6,2]],"date-time":"2007-06-02T20:57:29Z","timestamp":1180817849000},"page":"261-267","source":"Crossref","is-referenced-by-count":71,"title":["Two NP\u2010Hard Art\u2010Gallery Problems for Ortho\u2010Polygons"],"prefix":"10.1002","volume":"41","author":[{"given":"Dietmar","family":"Schuchardt","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hans\u2010Dietrich","family":"Hecker","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2006,11,13]]},"reference":[{"key":"e_1_2_1_2_2","volume-title":"Computers and Intractability","author":"Garey M. R.","year":"1979"},{"key":"e_1_2_1_3_2","doi-asserted-by":"crossref","unstructured":"Lee D. T. andA. K.Lin Computational complexity of art\u2010gallery problems. IEEE Trans. Information Theory IT\u201032 No.2 (1986).","DOI":"10.1109\/TIT.1986.1057165"},{"key":"e_1_2_1_4_2","volume-title":"Art Gallery Theorems and Algorithms","author":"O'Rourke J.","year":"1987"}],"container-title":["Mathematical Logic Quarterly"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fmalq.19950410212","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/malq.19950410212","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,26]],"date-time":"2023-10-26T19:51:20Z","timestamp":1698349880000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/malq.19950410212"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1995,1]]},"references-count":3,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1995,1]]}},"alternative-id":["10.1002\/malq.19950410212"],"URL":"https:\/\/doi.org\/10.1002\/malq.19950410212","archive":["Portico"],"relation":{},"ISSN":["0942-5616","1521-3870"],"issn-type":[{"value":"0942-5616","type":"print"},{"value":"1521-3870","type":"electronic"}],"subject":[],"published":{"date-parts":[[1995,1]]}}}