Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van toi hoc snippets" » "van tai hoc snippets", "van thi hoc snippets", "van toan hoc snippets", "van hoi hoc snippets", "van toc hoc snippets", "van tri hoc snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core snippets"

Try widening your search to All Fields.

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• Performing a fuzzy search may retrieve terms with similar spellings: (((("van toi hoc snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("van toi hoc snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
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