Perhaps you should try some spelling variations:
"sung and moon letters" » "dung and moon letters", "song and moon letters", "ung and moon letters", "sung and muon letters", "sung and yoon letters", "sung and soon letters"
"sung and mon letters" » "dung and mon letters", "song and mon letters", "ung and mon letters"
"cung and moon letters" » "cung and muon letters", "cung and yoon letters", "cung and soon letters", "cong and moon letters", "dung and moon letters"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("sung and moon letters") OR ("cung and moon letters"))) or ("sung and mon letters"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("sung and moon letters") OR ("cung and moon letters"))) OR ("sung and mon letters")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"sung and moon letters\") OR (\"cung and moon letters\"))) or (\"sung and mon letters\"))".
• Removing quotes may allow a broader search: (((( sung and moon letters ) OR ( cung and moon letters ))) or ( sung and mon letters )).
• Adding a wildcard symbol may retrieve word variants: (((("sung and moon letters") OR ("cung and moon letters"))) or ("sung and mon letters"))*.