Subroutes in backbone?

Submodules

    app_router.on('route:showProjects', function(){
       	require(['views/projects/ProjectsView',],
	        function(ProjectsView){
	          	//sub routes
                var ProjectRoutes = Backbone.Router.extend({
                    routes : {
                        'clients/:id': 'showClients'
                    }
                })
                
                var projectRoutes = new ProjectRoutes();
                
                projectRoutes.on('route:clients', function(id){
                    //require and run view
                })

                var projectsView = new ProjectsView();
        		projectsView.render();
	       }
	    );    
    });