<h4>Boolean Operators <b>AND</b>, <b>OR</b>, <b>NOT</b></h4>
<p>When you use the <b>Simple Search</b>, all terms are combined by <b>AND</b> automatically. For a more tightly focused search you may use the 
Boolean Operators to combine different search terms.</p>
<p><b>AND:</b> The document has to contain all search terms.</p>
<p><b>OR:</b> The document has to contain one of the search terms. This function broadens your search and is recommended, when there are 
different terms for the same meaning.</p>
<blockquote>article <b>OR</b> paper</blockquote>
<p><b>NOT:</b> This function works excluding and might be useful to reduce a large result list: Documents, which contain the one term, may not contain 
the other.</p>
<blockquote>article <b>NOT</b> paper</blockquote>
The Boolean Operators work for the <b>Advanced Search</b> as well. You may use them to combine different search terms within one search field. For example,
to search for documents of the author "Doe" in the years 2002 or 2003, use the query:
<blockquote>Author: Doe <br> Year: 2002 <b>OR</b> 2003</blockquote>
<h4>Wildcards</h4>
<p>In the field 'Search:', you may use the symbols '*' and '?' as wildcards. Use them in place of a character or characters that are unknown or that 
may differ. You cannot use them in front of a word or search string.</p>
<blockquote>Example 1: <b>chemi*</b> finds <i>chemical</i> but also <i>chemistry</i> or <i>chemist</i>.</blockquote>
<blockquote>Example 2: <b>licen?e</b> finds <i>licence</i> and <i>license</i>.</blockquote>
<p>You may use double quotes (") to search for phrases.</p>
