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