Perhaps you should try some spelling variations:
"dung nghien mo snippets" » "duong nghien mo snippets", "dung chien mo snippets", "dong nghiep mo snippets", "dung nghien o snippets", "dung nghiep mo snippets", "dung nghiem mon snippets"
"using java code snippets" » "using data code snippets"
"locating bug core snippets" » "locating bug 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 nghien mo snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using java code snippets") OR ("dung nghien mo snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( using java code snippets ) or ( dung nghien mo snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using java code snippets") or ("dung nghien mo snippets"))) or ("locating bug core snippets"))*.