Perhaps you should try some spelling variations:
produc » produce, products, produced
product » producet, productst, producedt, products
productttvity » producetttvity, productstttvity, producedtttvity, productsttvity, producttvity, productivity, producitvity
producettse » produceettse, productsettse, producedettse
produzieren » reduzieren

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((produc OR product) OR (productttvity OR (producettse OR produzieren))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((produc OR product) or (productttvity or (producettse or produzieren)))".
• Adding a wildcard symbol may retrieve word variants: ((produc OR product) or (productttvity or (producettse or produzieren)))*.