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