Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van tuan doc snippets" » "van quan doc snippets", "van ban doc snippets", "anh tuan doc snippets", "van than doc snippets", "van tuan 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 tuan doc 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 tuan doc snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van tuan doc snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van tuan doc snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.