Route blank

Kenapa route yang localhost:8000/admin/users/role dan localhost:8000/admin/users/permission tidak bisa diakses malah blank

 <?php
Route::group(['prefix' => 'admin', 'as'=>'backend.',  'middleware' => 'auth'], function()
{
	Route::get('/', 'AdminController@index');
	//users
	Route::resource('/users','UsersController');
	Route::resource('/users/role','RoleController');
	Route::resource('/users/permission','PermissionController');

});
?>