DITA topics can indeed contain multiple external links, allowing authors to reference several external resources or websites within a single topic. This flexibility is valuable for providing readers with diverse sources of information or related content that enhances the understanding of the topic. These links can be used to connect readers to various external references, making DITA content more comprehensive and informative.

Here is an example of how a DITA topic can include multiple external links:

<!-- Example of a DITA Topic with Multiple External Links -->
<p>In our research, we found several relevant external resources that you may find useful. Please explore the following links for more information:</p>
<ul>
  <li><link href="https://www.example1.com" title="External Link 1">External Resource 1</link></li>
  <li><link href="https://www.example2.com" title="External Link 2">External Resource 2</link></li>
  <li><link href="https://www.example3.com" title="External Link 3">External Resource 3</link></li>
</ul>

In this example, the <link> element is used to create multiple external links, each with its own href attribute specifying the URL and a title attribute defining the link’s title or label. The external links are organized in an unordered list for clear presentation. This approach allows authors to include multiple external references in a single DITA topic, making it a comprehensive and valuable resource for readers.