Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van lu moi snippets" » "van luc moi snippets", "van du moi snippets", "van le moi snippets", "van lu hoi snippets", "van ly moi 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 lu moi 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 lu moi snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van lu moi snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van lu moi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.