$re = '/^((?:.+?, .+?;)*?(?:[^;\s]+?, .+?)\.)([^;]+?\.).*$/m';
$str = 'DI MAIO, P. The Missing Pragmatic Link in the Semantic Web. Business Intelligence Advisory Service Executive Update. v. 8, n. 7, 2008.
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EDMONDS, B. The Pragmatic Roots of Context. In: PROC. OF THE 2ND INTERNATIONAL AND INTERDISCIPLINARY CONFERENCE ON MODELING AND USING CONTEXT. Berlin; Heidelberg; New York, v. 1688, 1999. Anais… v. 1688, p. 119-132, 1999.
BERNERS-LEE, T. Semantic Web Concepts. 2005a. Disponível em: http://www.w3.org/2005/Talks/0517-boit-tbl. Acesso em: 25 set. 2014
BERNERS-LEE, T. Web for real people. 2005b. Disponível em . Acesso em: 25 set. 2014.
BERNERS-LEE, T.; CAILLIAU, R. WorldWideWeb: Proposal for a HyperText Project. 1990. Disponível em: < http://www.w3.org/Proposal.html >. Acesso em: 13 out. 2014.
BERNERS-LEE, T.; HENDLER, J.; LASSILA, O. The semantic web: a new form of web content that is meaningful to computers will unleash a revolution of new possibilities. New York: Scientific American, 2001. Disponível em: http://www.sciam.com/2001/050lissue/0501berners-lee.html. Acesso em: 13 out. 2014.';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php