$re = '/(\bafter[\s_:.,()-]+|\bnach[\s_:.,()-]+|\bd\'apres[\s_:.,()-]+|\bd´apres[\s_:.,()-]+|\bCircle of[\s_:.,()-]+)*(Pablo[\s_:.,()-]+Picasso|Picasso[\s_:.,()-]+Pablo)([\s_:.,()-]+Nachfolge\b|[\s_:.,()-]+Nachfolger\b|[\s_:.,()-]+Nachfolgerin\b|[\s_:.,()-]+Werkstatt\b|[\s_:.,()-]+Umkreis\b|[\s_:.,()-]+d\'apres\b|[\s_:.,()-]+d´apres\b|[\s_:.,()-]+Circle of\b)*/uim';
$str = 'This is a test Picasso, Pablo bla
This is a test after Pablo Picasso (d\'apres)';
preg_match_all($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