Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van danh du snippets" » "van doanh du snippets", "van anh du snippets", "van hanh du snippets", "van danh dau snippets", "van danh tu snippets", "van dinh du 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 danh du 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 danh du snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van danh du snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van danh du snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.