Perhaps you should try some spelling variations:
workers volunteer » workers volunteers, worker volunteer, others volunteer
infants treatment » its treatment, effects treatment, agents treatment
new workers » new yorker, new markers, line workers
infantry » infant, infancy
regiment » regimen, regimes, regime

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: (( 7th new workers volunteer infantry regiment ) OR ( 7th new workers volunteer ((infants treatment) OR (implants treatment)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( 7th new workers volunteer infantry regiment ) or ( 7th new workers volunteer ((infants treatment) OR (implants treatment)) ))".
• Adding a wildcard symbol may retrieve word variants: (( 7th new workers volunteer infantry regiment ) or ( 7th new workers volunteer ((infants treatment) OR (implants treatment)) ))*.