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

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