Perhaps you should try some spelling variations:
medical laboratories » chemical laboratories, medical laboratory, clinical laboratories
virtual laboratories » virtual laboratory
federal laboratories » chemical laboratories, research 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 (virtual laboratories))) OR (federal laboratories)).
• Adding a wildcard symbol may retrieve word variants: ((((medical laboratories) or (virtual laboratories))) or (federal laboratories))*.