code: def publication_info2marc(self, key, values):
      
      result_773 = self.get('773', [])
      result_7731 = self.get('7731', [])
  
      for value in force_list(convert_new_publication_info_to_old(values)):
          page_artid = []
          if value.get('page_start') and value.get('page_end'):
              page_artid.append(u'{page_start}-{page_end}'.format(**value))
          elif value.get('page_start'):
              page_artid.append(u'{page_start}'.format(**value))
          elif value.get('artid'):
              page_artid.append(u'{artid}'.format(**value))
  
          result = {
              '0': get_recid_from_ref(value.get('parent_record')),
              'c': page_artid,
              'm': value.get('material'),
              'n': value.get('journal_issue'),
              'p': value.get('journal_title'),
              'q': value.get('conf_acronym'),
              'r': value.get('parent_report_number'),
              'v': value.get('journal_volume'),
              'w': value.get('cnum'),
              'x': value.get('pubinfo_freetext'),
              'y': value.get('year'),
              'z': value.get('parent_isbn'),
          }
  
          if value.get('hidden'):
              result_7731.append(result)
          else:
              result_773.append(result)
  
      self['7731'] = result_7731
      return result_773
docs: Populate the ``773`` MARC field.
  
      Also populates the ``7731`` MARC field through side effects.