Perhaps you should try some spelling variations:
"python missing data snippets" » "python using data snippets"
"locating bug core snippets" » "locating bug code snippets"
"da doi dan snippets" » "da hoi dan snippets", "da doi ban snippets", "da doi dau snippets", "va doi dan snippets", "da di dan snippets", "da dot dan snippets"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("da doi dan snippets") or ("python missing data snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("da doi dan snippets") OR ("python missing data snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( da doi dan snippets ) or ( python missing data snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("da doi dan snippets") or ("python missing data snippets"))) or ("locating bug core snippets"))*.