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WikiPedia: Nguồn gốc ngôn ngữ http://www.christenebrowne.com/video-on-demand/ http://pubman.mpdl.mpg.de/pubman/item/escidoc:5271... http://adsabs.harvard.edu/abs/2010Sci...329.1600E http://pandora.cii.wwu.edu/vajda/ling201/test1mate... http://pandora.cii.wwu.edu/vajda/ling201/test4mate... //www.ncbi.nlm.nih.gov/pubmed/5875341 http://www.accessexcellence.org/BF/bf02/klein/inde... http://center-for-nonverbal-studies.org/htdocs/970... //dx.doi.org/10.1006%2Fanbe.1994.1149 //dx.doi.org/10.1016%2F0022-5193(64)90038-4