TS2307: Cannot find module 'angular'

There are many questions on this exact error. Nevertheless, I cannot find one that fixes my problem. I'm probably missing something simple but I don't know what.

In my project I just created the first ts file - initialize.ts:

import angular from "angular";

namespace AngularTypeScriptStarterKit {
    angular
        .module('app', []);

}

Now the problem is that 'angular' is marked with red, saying:

TS2307: Cannot find module 'angular'

I have the declarations file for angular located at /typings/globals/angular/index.d.ts

Any help will be profoundly appreciated.

typings.json:

{
  "globalDependencies": {
    "angular": "registry:dt/angular#1.5.0+20160725073351",
    "jquery": "registry:dt/jquery#1.10.0+20170310222111"
  },
  "dependencies": {
    "angular": "registry:dt/angular#1.6.0+20170321201455"
  }
}

Please let me know for any other required information and I'll update my question.

via Alon