Perhaps you should try some spelling variations:
"heir apparent" » "huir apparent", "weir apparent", "herr apparent", "heir apparently", "heir aparente", "heir apaparente", "heir apparental"
"heir apparental" » "huir apparental", "weir apparental", "herr apparental", "heir apparentlyal", "heir aparenteal", "heir parental", "heir apparently", "heir aparentan", "heir apaparenteal", "heir apparentalal"
"her apaparente" » "her aparente", "her apaaparentee", "her apaparentale"
"hair parent" » "hair aparente", "hair parental"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((((("heir apparent") OR ("heir apparental"))) OR ("her apaparente"))) OR ("hair parent"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"heir apparent\") OR (\"heir apparental\"))) OR (\"her apaparente\"))) OR (\"hair parent\"))".
• Removing quotes may allow a broader search: (((((( heir apparent ) OR ( heir apparental ))) OR ( her apaparente ))) OR ( hair parent )).
• Adding a wildcard symbol may retrieve word variants: (((((("heir apparent") OR ("heir apparental"))) OR ("her apaparente"))) OR ("hair parent"))*.