The Keystone XL Pipeline: Everything You Need To Know - NRDC
Keystone Pipeline - Wikipedia
Keystone XL Pipeline: What it Means, How it Works - Investopedia
Keystone XL pipeline: Why is it so disputed? - BBC News
What Is the Keystone XL Pipeline — and Why Is It So …
Everything you need to know about the Keystone XL pipeline
A look at the history of the Keystone XL pipeline expansion
Keystone XL Pipeline – Environmental and Energy Law Program