Simplify the following text for a Grade 11 native English-speaking person.
Original: And Holocaust historian Robert Melvin Spector concludes that the Nazis `` did indeed use human fat for the making of soap at Stutthof , '' albeit in limited quantity .
Simplified: Holocaust historian Robert Melvin Spector says that the Nazis `` did indeed use human fat for the making of soap at Stutthof , '' but in limited quantity .