How to force VS2013 to do Intellisence for adjacent JS files?

Question

JavaScript

Good afternoon,
VS2013 Community, opened a directory on drive C as a "website" with a saved template for a simple site:
-[css]
-[js]
-Index.html
In the js folder I have backbone.js and underscore.js.
And also my main.js
When editing main.js, I can't get Intellisence enabled for the backbone.
Specified special links at the beginning of main.js saved everything as a solution. Does not help.

/// <reference path="underscore.js" />
/// <reference path="backbone.js" />

At the same time, the Brackets editor picked up everything instantly without any links.
What is the problem with VS?
Thanks in advance.