Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Neutrino:

"

As well as specific sources, a general background level of neutrinos is expected to pervade the universe, theorized to occur due to two main sources: the Big Bang and supernova. Around 1 second after the Big Bang, neutrinos decoupled, giving rise to a background level of neutrinos known as the cosmic neutrino background (CNB). A second diffuse neutrino background is supernova-originated.[citation needed]