Perhaps you should try some spelling variations:
"mang viet can snippets" » "nang viet can snippets", "anh viet can snippets", "mai viet can snippets", "mang viet van snippets", "mang viet ca snippets", "mang vien can snippets"
"hang java java snippets" » "hang 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: (((("mang viet can snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("mang viet can snippets") OR ("hang java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( mang viet can snippets ) or ( hang java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("mang viet can snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))*.