<p>You can also try searching the 'Computer Science' section of arXiv: <a href="http://arxiv.org" rel="nofollow noreferrer">http://arxiv.org</a> for "search engine" and the various terms that others have suggested.</p>

<p>It contains many academic papers, all freely available... hopefully some of them will be relevant to your research. (Of course the caveat of validating any paper's content applies.)</p>
How does Google use HTML tags to enhance the search engine?
<p>I know that Google’s search algorithm is mainly based on pagerank. However, it also does analysis and uses the structure of the document <code>H1</code>, <code>H2</code>, <code>title</code> and other HTML tags to enhance the search results.</p>

<p><strong>What is the name of this technique "using the document structure to enhance the search results"?</strong></p>

<p>And are there any academic papers to help me study this area?</p>

<p>The fact that Google is taking the HTML structure into account is well covered in SEO articles however I could not find it in the academic papers.</p>