PDF extraction fix; DOI issues (closes bug #290)
PDF extraction fix; DOI issues (closes bug #290)

pombredanne/paperpile,jondo/paperpile,jondo/paperpile,pombredanne/paperpile,jondo/paperpile,pombredanne/paperpile,jondo/paperpile,pombredanne/paperpile,jondo/paperpile,pombredanne/paperpile