You don't need a list of places to look. Start looking for info that answers the question.

Use gifs to make sources more accessible for students. https://gifmaker.me/

Use transparent boxes in different colors to overlay and highlight specific portions of text to help focus students' reading.

Once you find a source, seek to create intentional gaps by looking for other sources that corroborate the source to get students to converse, interpret, create inferences. This is what fills the gaps.

The source needs to say something about human beings.

Always research anything you find on social media to determine accuracy.

Don't always give students titles of sources. Use this to engage them.

Make sources being used together about the same size.

It's not always about simplified sources. It's about accessible sources.