http://app.msf.gov.sg/Portals/0/Summary/research/Chapter%201%20-%20Demographic%20Realities.pdf
http://www.singstat.gov.sg/docs/default-source/default-document-library/publications/publications_and_papers/population_and_population_structure/population2014.pdf
http://www.eastshorepark.org/benefits_of_parks%20tpl.pdf
https://www.ndsu.edu/pubweb/chiwonlee/plsc211/student%20papers/articles08/CassiSchriefer/Cassi's%20Website/Cassi'sWebsite.html
http://www.singstat.gov.sg/docs/default-source/default-document-library/publications/publications_and_papers/population_and_population_structure/population2014.pdf
http://www.eastshorepark.org/benefits_of_parks%20tpl.pdf
https://www.ndsu.edu/pubweb/chiwonlee/plsc211/student%20papers/articles08/CassiSchriefer/Cassi's%20Website/Cassi'sWebsite.html