Perhaps you should try some spelling variations:
"dung lua code snippets" » "dung luan code snippets", "dung luat code snippets", "dung cua code snippets", "dung bug code snippets", "dung lbm code snippets"
"locating bug core snippets" » "locating bug code snippets"
"dong va java snippets" » "dung va java snippets", "dong ha java snippets", "luong va java snippets", "dong java java 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: (((("dong va java snippets") or ("dung lua code snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dong va java snippets") OR ("dung lua code snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( dong va java snippets ) or ( dung lua code snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong va java snippets") or ("dung lua code snippets"))) or ("locating bug core snippets"))*.