Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van toi hoan snippets" » "van thi hoan snippets", "van tri hoan snippets", "van toi hoat snippets", "van tai hoan snippets", "van toan hoan 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 toi hoan 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 toi hoan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van toi hoan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van toi hoan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.