Perhaps you should try some spelling variations:
"dung trien o snippets" » "dung tren o snippets", "dung tien o snippets", "dung chien o snippets", "dung trien bao snippets", "dung trien cho snippets", "dung trien ton snippets"
"python using java snippets" » "python using data 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: (((("dung trien o snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung trien o snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
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