Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"duc khoa de snippets" » "duoc khoa de snippets", "duc hoa de snippets", "dac khoa de snippets", "duc khoa dr snippets", "duc khoa he snippets", "duc khoi de 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: (((("duc khoa de snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("duc khoa de snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duc khoa de snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duc khoa de snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.