Iron router don't see importing collections

Hi ! I have two app for one data base ( compose.io )
For second app I just make import for DB

before all works is fine, but now I start to do product page and I created path Router.route(’/product_page/:_id’, function () { …
… ,
data: function() {
return WHArticles.findOne(this.params._id);

}

So router don`t see this.params._id
and I don’t know what should to do for fix it

( Sorry for my English ) if some not clear, please ask me …