{"id":"000510149","type":"article","title":"Een schildknop uit Zwammerdam - Nigrum Pullum, gem. Alphen (Z.H.), 1. Vondstomstandigheden en beschrijving","pages":"242-249","container-title":"Helinium, 10.1970","author":[{"family":"Haalebos","given":"J.K."}],"issued":{"raw":"1970"}}