use strict;
use warnings;

my $raw = '<P_contrib-author>Allan Wigfield, Susan L. Klauda, and Jenna Cambria</P_contrib-author>';

$raw =~ s/<P_contrib-author>|<\/P_contrib-author>//g;

print "<contrib-group>\n";
for (split /, (?:and )?/, $raw) {
    m/(.*) (.*)/;
    print "<name><surname>$2</surname><given-names>$1</given-names></name>\n";

}
print "</contrib-group>";