Perhaps you should try some spelling variations:
"medical physics and engineering" » "medical physical and engineering"
"chemical physics and engineering" » "chemical physical and engineering"
"mathematical physics and engineering" » "mathematical physical and engineering", "mathematics physics and engineering"

Try widening your search to All Fields.

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