In the YouTube description of his video, he gave this list of sources, including a VDARE.com column from 2002: Why Not Just Give Them A Roomful Of Gold? Or: Immigration – Just Another Government Program.

Sources: http://www.wnd.com/2015/04/the-real-i... http://www.nber.org/digest/may07/w125... http://www.pressreader.com/usa/the-wa... http://www.hispanicvista.com/HVC/Colu... /articles/why-not... http://dailycaller.com/2014/01/16/the... http://www.americanthinker.com/2014/0... http://www.forbes.com/sites/jamesdorn... http://link.springer.com/article/10.1...