Perhaps you should try some spelling variations:
hospital laboratories » clinical laboratories, medical laboratories
federal laboratories » research laboratories, virtual laboratories, bell laboratories
medical laboratory » clinical laboratory

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((((hospital laboratories) OR (medical laboratory))) OR (((federal laboratories) OR (chemical laboratories))))".
• Adding a wildcard symbol may retrieve word variants: ((((hospital laboratories) OR (medical laboratory))) OR (((federal laboratories) OR (chemical laboratories))))*.