Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van viet voi snippets" » "san viet voi snippets", "gian viet voi snippets", "tran viet voi snippets", "van viec voi snippets", "van viet doi snippets", "van viet duoi 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: (((("van viet voi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("van viet voi snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van viet voi snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van viet voi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.