It's good practice in real world to reference reliable sources that was used to create an article/book etc. Same situation in the online space - it's good practice, specially from moral point of view.

If you strictly look from SEO point of view, your "link juice" flows to referenced pages. It doesn't hurt your website, but it helps referenced websites.

For me, it's like giving credit and showing respect to your sources.

Hello, we have a website that publishes insights about sustainable urban development, is it good practice for SEO to include source references within the articles? It can be as many as up to 40 references per article. There is a pdf version that users can download that includes all the references, but they don't give the search engine everything it desires when analyzing and ranking pages.