Many supermassive black holes can't be seen with current technology - Earth.com
- Many supermassive black holes can't be seen with current technology Earth.com
- How Many Black Holes Are Hiding? NASA Study Homes in on Answer NASA
- Feeding supermassive black holes are more common than thought across the universe Space.com
- NASA Astronomers Zero In on the Number of Hidden Supermassive Black Holes Gizmodo
- Many more black holes could be ‘hiding’ in the universe than previously thought The Independent