Perhaps you should try some spelling variations:
study industrial » early industrial
industrial air » industrial age, industrial art, industrial base
notes regional » does regional, norms regional, states regional
der regional » der regionale, der regionalen, der region
per regional » power regional, der regionale, spur regional

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: study industrial air ((notes regional) OR (((der regional) OR (per regional)))) disparities.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "study industrial air ((notes regional) or (((der regional) OR (per regional)))) disparities.~".
• Adding a wildcard symbol may retrieve word variants: study industrial air ((notes regional) or (((der regional) OR (per regional)))) disparities.*.