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 Arterial blood:

This text has been unreferenced on Wikipedia for a very long time. If you can't find a source, be bold and remove it!

This text is part of the article's lead section, so referencing it may be optional. Please see WP:CITELEAD for more information.

"

Arterial blood is the oxygenated blood in the circulatory system found in the pulmonary vein, the left chambers of the heart, and in the arteries.[1] It is bright red in color, while venous blood is dark red in color (but looks purple through the translucent skin). It is the contralateral term to venous blood.[citation needed]