Perhaps you should try some spelling variations:
"using java code snippets" » "using data code snippets", "using java core snippets"
"van thinh he snippets" » "van thanh he snippets", "van chinh he snippets", "van minh he snippets", "van thinh le snippets", "van trinh he snippets", "van hinh he snippets"
"locating bug code snippets" » "locating bug core snippets", "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 ("van thinh he snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using java code snippets") OR ("van thinh he snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using java code snippets ) or ( van thinh he snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using java code snippets") or ("van thinh he snippets"))) or ("locating bug code snippets"))*.