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