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