fix potential bug

pmc_open_access_xml.py

@@ -181,14 +181,14 @@ def parseout_el_refs(el, rids):
                         tail = ", "
                     elif ref_rstart is not None:
                         ref_rstop = int(res_reftext[ref_class][-1])
-                        ref_kword = [ref_kword]
+                        new_ref_kwords = [ref_kword]
                         for i in range(ref_rstart+1, ref_rstop):
                             new_rid = re.sub(str(ref_rstop), str(i), rid, count=1)
                             ref_idx_, ref_kword_, ref_class_ = rids[new_rid]
                             res_rid[ref_class_].insert(-1, ref_idx_)
                             res_reftext[ref_class_].insert(-1, str(i))
-                            ref_kword.insert(-1, ref_kword_)
-                        ref_kword = ", ".join(ref_kword)
+                            new_ref_kwords.insert(-1, ref_kword_)
+                        ref_kword = ", ".join(new_ref_kwords)
                         ref_rstart = None
             except (KeyError, ValueError):
                 ref_rstart = None