$re = '/\w+,\s*\w+\s*\([^()]*(?:\([^()]*\)[^()]*)*\);?/m';
$str = 'Smith, Anna (Univ Cambridge); Doe, Jane (Univ Vienna (Austria)); Doe, John (Univ Tokyo; MIT)
Mueller, Hans (FU Berlin (Germany)); Schmid, Julia (); Doe, John (CalTech); Boe, Jane (TU Wien)
Kim, Lee (Nazarbayev Univ (Kazakhstan); Univ Oxford)';
preg_match_all($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