18. The one or more tangible computer-readable storage media of claim 17 , wherein, when multiple portions in the plurality of portions each include the highest number of the one or more keywords, the abstract is the one of the multiple portions that has a greatest total number of the keywords, including keywords that are repeated.
17. The one or more tangible computer-readable storage media of claim 9 , wherein each portion has a length that does not exceed the length limit.