var func1 = function() {
    // console.log(this.source1);   // wont work, makes sense
    // console.log(source1);        // wont work, wish it would
    console.log(this.source2);      // works fine
    console.log(source2);           // works fine
};
var func2 = function() {
    var source1 = "source1";
    this.source2 = "source2";
    func1.call(this);
}();
var func3 = function() {
    var source3 = "source3";
    var func4 = function() {
        console.log(source3); // also works fine, makes sense
    }();
}();

var module = (function() {
    var source1;
    var source2;

    var func1 = function() {
        console.log(source2);           // works fine
    };
    var func2 = function() {
        source1 = "source1";
    }();
    var func3 = function() {
        var func4 = function() {
            console.log(source1); // also works fine, makes sense
        }();
    }();

    return {
      func1: func1,
      func2: func2,
      func3: func3
    };

}());

// Then invoke them.
module.func2();
module.func1();

var func1 = module.func1;
var func2 = module.func2;
var func3 = module.func3;