Match the words with the pictures. What unites all these things?

1 - d (post cards), 2 - b (coins), 3 - e (chocolate wrappers), 4 - h (matchboxes), 5 - a (calendars), 6 - g (butterflies), 7 - f (teddy bears), 8 - c (dolls). Все эти предметы можно коллекционировать.