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