Perhaps you should try some spelling variations:
"heir apparent" » "huir apparent", "her apparent", "weir apparent", "heir apparently", "heir aparente", "heir parent"
"heir apparental" » "huir apparental", "her apparental", "weir apparental", "heir apparentlyal", "heir aparenteal", "heir parental", "heir apparently", "heir aparentan"
"heir aparentely" » "huir aparentely", "her aparentely", "weir aparentely", "heir aparente", "heir apparently", "heir aparentes"
"heir parental" » "huir parental", "her parental", "weir 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 apparental\"))) OR (\"heir aparentely\"))) OR (\"heir parental\"))~".
• Removing quotes may allow a broader search: (((((( heir apparent ) OR ( heir apparental ))) OR ( heir aparentely ))) OR ( heir parental ))~.
• Adding a wildcard symbol may retrieve word variants: (((((("heir apparent") OR ("heir apparental"))) OR ("heir aparentely"))) OR ("heir parental"))*.