code: def line_chunker(text, getreffs, lines=30):
      
      level = len(text.citation)
      source_reffs = [reff.split(":")[-1] for reff in getreffs(level=level)]
      reffs = []
      i = 0
      while i + lines - 1 < len(source_reffs):
          reffs.append(tuple([source_reffs[i]+"-"+source_reffs[i+lines-1], source_reffs[i]]))
          i += lines
      if i < len(source_reffs):
          reffs.append(tuple([source_reffs[i]+"-"+source_reffs[len(source_reffs)-1], source_reffs[i]]))
      return reffs
docs: Groups line reference together
  
      :param text: Text object
      :type text: MyCapytains.resources.text.api
      :param getreffs: Callback function to retrieve text
      :type getreffs: function(level)
      :param lines: Number of lines to use by group
      :type lines: int
      :return: List of grouped urn references with their human readable version
      :rtype: [(str, str)]