Perhaps you should try some spelling variations:
"using java code snippets" » "using data code snippets", "using java core snippets", "using java code slippers"
"dung van hieu snippets" » "duong van hieu snippets", "dung va hieu snippets", "dang van hieu snippets", "dung cao hieu snippets", "dung van hieu slippers"
"locating bug code snippets" » "locating bug core snippets", "locating bug code slippers", "locating bung code snippets", "locating bugs code 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 ("dung van hieu snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using java code snippets") OR ("dung van hieu snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using java code snippets ) or ( dung van hieu snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using java code snippets") or ("dung van hieu snippets"))) or ("locating bug code snippets"))*.