Perhaps you should try some spelling variations:
chemical entitiess » chemical quantities, chemical engineers, clinical entities
electrical engines » electrical engine, electrical engineers, electrical engineer's
chemical entities » clinical entities, chemical societies, chemical engineers

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: (( chemical entities ) OR ((( electrical engines ) OR ( chemical entitiess )))).
• Adding a wildcard symbol may retrieve word variants: (( chemical entities ) or ((( electrical engines ) or ( chemical entitiess ))))*.