Perhaps you should try some spelling variations:
"american physical unit" » "american chemical unit", "american political unit", "american physical units", "american physical unity", "american physical und"
"american medical unit" » "american chemical unit", "american medical use", "american medical uses", "american medical ai"

You may be able to get more results by adjusting your search query.

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