Perhaps you should try some spelling variations:
"chon truong cac snippets" » "hoc truong cac snippets", "cao truong cac snippets", "con trung cac snippets", "chon truong cao snippets", "chon trong cac snippets", "chon truong ca snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: (((("dung java java snippets") or ("chon truong cac snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung java java snippets") OR ("chon truong cac snippets"))) OR ("locating bug code snippets")).
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• Adding a wildcard symbol may retrieve word variants: (((("dung java java snippets") or ("chon truong cac snippets"))) or ("locating bug code snippets"))*.