Perhaps you should try some spelling variations:
"using java core snippets" » "using data core snippets"
"van danh viet snippets" » "van anh viet snippets", "van ninh viet snippets", "van nang viet snippets", "van doanh viet snippets", "van hanh viet snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using java core snippets") OR ("van danh viet snippets"))) OR ("locating bug code snippets"))~.
• Removing quotes may allow a broader search: (((( using java core snippets ) or ( van danh viet snippets ))) or ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("using java core snippets") or ("van danh viet snippets"))) or ("locating bug code snippets"))*.