https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5663018/
https://www.carnegieuktrust.org.uk/blog/more-than-just-a-walk-in-the-park/
https://www.euro.who.int/__data/assets/pdf_file/0010/337690/FULL-REPORT-for-LLP.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6209905/
http://www.gardinergreenribbon.com/why-parks-are-important/