Perhaps you should try some spelling variations:
"quoc hang cac snippets" » "quoc thang cac snippets", "quoc hung cac snippets", "quoc hanh cac snippets", "quoc hang ca snippets", "quoc hang cau snippets", "quoc bang cac snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: (((("quoc hang cac snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("quoc hang cac snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( quoc hang cac snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("quoc hang cac snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.