Perhaps you should try some spelling variations:
"heir apparent" » "huir apparent", "her apparent", "hair apparent", "heir aparente", "heir apaparente", "heir apparental"
"heir apparently" » "huir apparently", "her apparently", "hair apparently", "heir aparentely", "heir apaparentely", "heir apparentally"
"heir parent" » "huir parent", "her parent", "hair parent", "heir aparente", "heir parental"
"weir apparently" » "weir aparentely", "weis apparently", "wei apparently", "weil apparently", "weir apaparentely", "weir apparentally"

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 apparently") OR ("weir apparently"))))) OR ("heir parent"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"heir apparent\") OR (((\"heir apparently\") OR (\"weir apparently\"))))) OR (\"heir parent\"))".
• Removing quotes may allow a broader search: (((( heir apparent ) OR ((( heir apparently ) OR ( weir apparently ))))) OR ( heir parent )).
• Adding a wildcard symbol may retrieve word variants: (((("heir apparent") OR ((("heir apparently") OR ("weir apparently"))))) OR ("heir parent"))*.