Galaxies and gravity (article)

There are more galaxies than even Carl Sagan imagined - Big Think

Our galaxy's impossible collision could break gravity

Do galaxies have a gravitational pull? - Quora

Gravitational Lensing

How many galaxies are in the Universe?

How are galaxies formed? - ABC Education

Seeing with Gravity: How invisible particles can be observed in

Astronomers may have found first known planet in another galaxy

Gravity - Wikipedia

Milky Way Has 4 Billion Years to Live — But Our Sun Will Survive

New map of the universe's cosmic growth supports Einstein's theory

How the Milky Way works