Perhaps you should try some spelling variations:
"locating bugs code snippets" » "locating bug code snippets"
"using java code snippets" » "using data code snippets"
"van hoang son snippets" » "van hoan son snippets", "quan hoang son snippets", "tran hoang son snippets", "van hoang van snippets", "van lang son snippets", "van giang son 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 java code snippets") or ("van hoang son snippets"))) or ("locating bugs code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using java code snippets") OR ("van hoang son snippets"))) OR ("locating bugs code snippets")).
• Removing quotes may allow a broader search: (((( using java code snippets ) or ( van hoang son snippets ))) or ( locating bugs code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using java code snippets") or ("van hoang son snippets"))) or ("locating bugs code snippets"))*.