[Vuejs]-Cant mount children component to ref

Since you are using the Version 1 of VueJS, usage is a bit different – check this demo http://jsbin.com/rupogesumo/edit?html,js,output

<v-paginator :resource.sync="comments" v-ref:vpaginator resource_url="{{route('api.item.comments', $item->pk_i_id)}}"></v-paginator>

Docs Reference: https://v1.vuejs.org/api/#v-ref