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

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