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ACM"],"published-print":{"date-parts":[[2016,6,24]]},"abstract":"<jats:p>\n            The universal constant\n            <jats:italic>\u03bb<\/jats:italic>\n            , the growth constant of polyominoes (think Tetris pieces), is rigorously proved to be greater than 4.\n          <\/jats:p>","DOI":"10.1145\/2851485","type":"journal-article","created":{"date-parts":[[2016,6,27]],"date-time":"2016-06-27T13:41:38Z","timestamp":1467034898000},"page":"88-95","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":27,"title":["<i>\u03bb<\/i>\n            &gt; 4"],"prefix":"10.1145","volume":"59","author":[{"given":"Gill","family":"Barequet","sequence":"first","affiliation":[{"name":"Technion - Israel Institute of Technology, Haifa, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G\u00fcnter","family":"Rote","sequence":"additional","affiliation":[{"name":"Freie Universit\u00e4t Berlin, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mira","family":"Shalah","sequence":"additional","affiliation":[{"name":"Technion - Israel Institute of Technology, Haifa, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"320","published-online":{"date-parts":[[2016,6,24]]},"reference":[{"key":"e_1_2_2_1_1","first-page":"3","article-title":"Every planar map is four colorable","volume":"21","author":"Appel K.","year":"1977","unstructured":"Appel , K. and Haken , W . 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