class TestCtrl {
    constructor($injector: IInjectorService) {...}
}

class TestCtrl {
    constructor($injector: ng.auto.IInjectorService) {...}
}

///<reference path="../path/to/typeDefinitions/angularjs/angular" />

import IInjectorService = ng.auto.IInjectorService;

class TestCtrl {
    constructor($injector: IInjectorService) {...}
}

import {IInjectorService} from '../path/to/typeDefinitions/angularjs/angular';

class TestCtrl {
    constructor($injector: IInjectorService) {...}
}

import {auto as ngAuto} from "angular";
var foo:ngAuto.IInjectorService;

class TestCtrl {
  myReference: any;
  constructor($injector: ng.auto.IInjectorService){
    myReference = $injector.get('name');
  }
}