Table for the 4 triples with object "Null" sorted by label

Subject	Predicate
mdb:aanmonstering-gron_nsm-Null	mdb:bronid
ns15:opvarenden-1047110	ns15:achternaam
ns15:opvarenden-1393555	ns15:achternaam
mdb:schipper: Nieboer, Harm H.	mdb:bronid