Beinertes avoti – Keystone

https://www.nrdc.org/stories/what-keystone-pipeline
https://www.pbs.org/newshour/nation/trump-administration-approves-keystone-pipeline-on-u-s-land
https://globalnews.ca/news/6448189/trump-approval-keystone-xl-pipeline/
https://ballotpedia.org/Keystone_XL_Pipeline_political_timeline
https://www.nytimes.com/2017/01/24/us/politics/keystone-dakota-pipeline-trump.html