Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van tham du snippets" » "van thanh du snippets", "van tuan du snippets", "van chat du snippets", "van thap du snippets", "van tham do snippets", "van pham duc 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 tham 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 tham du snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van tham du snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van tham du snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.