News article about the opening of the new battery factory (from newspaper Het Centrum 6-2-1930)
"FABRIEK C. HERBERHOLD.". "Het Centrum". Utrecht, 1930/02/26 00:00:00, p. 6.
Article retrieved through Delpher on 15-07-2020, http://resolver.kb.nl/resolve?urn=ddd:010003094:mpeg21:p006