Perhaps you should try some spelling variations:
"python missing data snippets" » "python using data snippets"
"locating bug core snippets" » "locating bug code snippets"
"thi dan so snippets" » "thi dan code snippets", "thi doan so snippets", "thi lan so snippets", "thi dai so snippets", "thi dan soc snippets", "thi dan su snippets", "thi dan mo 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: (((("thi dan so snippets") or ("python missing data snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("thi dan so snippets") OR ("python missing data snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( thi dan so snippets ) or ( python missing data snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("thi dan so snippets") or ("python missing data snippets"))) or ("locating bug core snippets"))*.