Perhaps you should try some spelling variations:
"practical engineering" » "physical engineering", "acoustical engineering", "structural engineering"
"electrical engineers" » "mechanical engineers", "chemical engineers"
"optical engineering" » "chemical engineering", "biomedical engineering"

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: (("electrical engineers") OR ((((("practical engineering") OR ("optical engineering"))) OR ("electrical engineering")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"electrical engineers\") or (((((\"practical engineering\") OR (\"optical engineering\"))) or (\"electrical engineering\"))))".
• Removing quotes may allow a broader search: (( electrical engineers ) or ((((( practical engineering ) OR ( optical engineering ))) or ( electrical engineering )))).
• Adding a wildcard symbol may retrieve word variants: (("electrical engineers") or ((((("practical engineering") OR ("optical engineering"))) or ("electrical engineering"))))*.