Perhaps you should try some spelling variations:
"using hanh cong snippets" » "using hanh code snippets", "song hanh cong snippets", "using high cong snippets", "using half cong snippets", "using thanh cong snippets", "using hang cong snippets", "using hanh dong snippets"
"locating bug core snippets" » "locating bug code snippets"
"dung java java snippets" » "dung va java 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: (((("using hanh cong snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using hanh cong snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( using hanh cong snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using hanh cong snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.