Perhaps you should try some spelling variations:
"azimuthal quantum number" » "azimuthal quantum punumber"
"azimuthal quantum numbers" » "azimuthal quantum punumbers"
"azimuth quantum number" » "azimuth quantum punumber"
"azimuth quantum punumbers" » "azimuth quantum pupunumbers", "azimuth quantum punumber", "azimuth quantum outnumbers", "azimuth quantum plumbers"

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: (((("azimuthal quantum number") OR ("azimuthal quantum numbers"))) OR ((("azimuth quantum number") OR ("azimuth quantum punumbers")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"azimuthal quantum number\") OR (\"azimuthal quantum numbers\"))) or (((\"azimuth quantum number\") or (\"azimuth quantum punumbers\"))))".
• Removing quotes may allow a broader search: (((( azimuthal quantum number ) OR ( azimuthal quantum numbers ))) or ((( azimuth quantum number ) or ( azimuth quantum punumbers )))).
• Adding a wildcard symbol may retrieve word variants: (((("azimuthal quantum number") OR ("azimuthal quantum numbers"))) or ((("azimuth quantum number") or ("azimuth quantum punumbers"))))*.