Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"den luc son snippets" » "dien luc son snippets", "dong luc son snippets", "den thuc son snippets", "den lac son snippets", "den luc sang snippets", "den quoc son 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: (((("den luc son snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("den luc son snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( den luc son snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("den luc son snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.