Perhaps you should try some spelling variations:
"lan tranh do snippets" » "lanh tranh do snippets", "luan tranh do snippets", "can tranh do snippets", "lan trinh do snippets", "lan thanh do snippets", "lan trang do 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: (((("lan tranh do snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("lan tranh do snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( lan tranh do snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("lan tranh do snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.