I was reading about possession on the particle の and it stated one of the ways you can show possession was
これ は だれ の かんばん ですか
and I was just wondering if this would also work
あの かさ は だれ の ですか
I'm not sure if you need to have something for the の to connect to or if you can just do it this way.
かんばん
-- 「かばん」じゃなくて看板?