1. https://www.idc.com/
2. https://en.wikipedia.org/wiki/Automatic_summarization
3. Advances in Automatic Text Summarization (The MIT Press) Abridged Edition, Inderjeet Mani
4. https://www.quora.com/What-are-the-real-world-applications-of-automatic-text-summarization
5. https://www.kdnuggets.com/2019/01/approaches-text-summarization-overview.html