code: def _get_related_series(parse_info):
          
          seriesother_tags = [x for x in parse_info.select('h5.seriesother')]
          sibling_tag = [x for x in seriesother_tags if x.text == 'Related Series'][0]
          siblings_tag = list(sibling_tag.next_siblings)
  
          # filter valid tag
          # valid tag is all tag before following tag
          # <h5 class="seriesother">Recommendations</h5>
          valid_tag = []
          keypoint_found = False
          for x in siblings_tag:
              # change keypoint if condition match
              if x.name == 'h5' and x.attrs['class'] == ['seriesother']:
                      keypoint_found = True
  
              if not keypoint_found and x.strip is not None:
                  if x.strip():
                      valid_tag.append(x)
              elif not keypoint_found:
                  valid_tag.append(x)
  
          # only one item found and it is 'N/A
          if len(valid_tag) == 1:
              if valid_tag[0].strip() == 'N/A':
                  return None
  
          # items are combination between bs4 and text
          # merge and return them as list of text
          if len(valid_tag) % 2 == 0:
              zipped_list = zip(valid_tag[::2], valid_tag[1::2])
              result = []
              for x in zipped_list:
                  result.append('{} {}'.format(x[0].text, x[1]))
              return result
  
          raise ValueError("Valid tag isn't recognizeable.\n{}".format("\n".join(valid_tag)))
docs: get related_series from parse info.
  
          :param parse_info: Parsed info from html soup.