Perhaps you should try some spelling variations:
"python using code snippets" » "python using cfd snippets", "python using one snippets"
"van dung de snippets" » "van dong de snippets", "xay dung de snippets", "tin dung de snippets", "van dung he snippets", "van dung dat snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code 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 dung de snippets") or ("python using code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("van dung de snippets") OR ("python using code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van dung de snippets ) or ( python using code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van dung de snippets") or ("python using code snippets"))) or ("locating bug code snippets"))*.