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