[Kiro]

From your link:

> In fact, DuckDuckGo gets its results from over four hundred sources. These include hundreds of vertical sources delivering niche Instant Answers, DuckDuckBot (our crawler) and crowd-sourced sites (like Wikipedia, stored in our answer indexes). We also of course have more traditional links in the search results, which we also source from a variety of partners, including Oath (formerly Yahoo) and Bing.

So in other words all the traditional link results are from Bing and Yahoo. The other 400 sources and their own crawler are only for things like Instant Answer boxes at the top (which are great btw).