Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van khi toan snippets" » "van chi toan snippets", "van ke toan snippets", "van bai toan snippets", "van nhi toan snippets", "ban khi toan 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 khi toan 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 khi toan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van khi toan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van khi toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.