If you are using an online bibliographic referencing tool, then select to create a reference of type “Webpage”– and put in the link. Check the data it can find automatically and fix it to be as correct and complete as possible.
For example, if you want to reference this UN report —
In your Works Cited or Bibliography, the entry will look like this in the alphabetical listing — in MLA style:
UN Refugee Agency. “UNHCR Global Trends 2015: Forced Displacement in 2015.” The UN Refugee Agency, UNHCR, 2015, http://www.unhcr.org/statistics/unhcrstats/576408cd7/unhcr-global-trends-2015.html. Accessed 19 Jan. 2017.
And in the body of your paper, this information source can be referenced using an in-text citation like this — in MLA style:
The UN Refugee Agency estimates that 65.3 million people were forcibly displaced in 2015.
Over 65.3 million were forcibly displaced in 2015 (UN Refugee Agency).