Perhaps you should try some spelling variations:
"heir apparent" » "huir apparent", "her apparent", "weir apparent", "heir apparently", "heir aparente", "heir apaparente", "heir apparental"
"heir aparenteal" » "huir aparenteal", "her aparenteal", "weir aparenteal", "heir aparente", "heir parental", "heir aparentan", "heir aaparenteeal", "heir aparentaleal"
"heir aparentalely" » "huir aparentalely", "her aparentalely", "weir aparentalely", "heir parentales", "heir aaparentealely", "heir aparentalalely"
"heir parent" » "huir parent", "her parent", "weir parent", "heir aparente", "heir parental"

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: "((((((\"heir apparent\") OR (\"heir aparenteal\"))) OR (\"heir aparentalely\"))) OR (\"heir parent\"))~".
• Removing quotes may allow a broader search: (((((( heir apparent ) OR ( heir aparenteal ))) OR ( heir aparentalely ))) OR ( heir parent ))~.
• Adding a wildcard symbol may retrieve word variants: (((((("heir apparent") OR ("heir aparenteal"))) OR ("heir aparentalely"))) OR ("heir parent"))*.