Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"duc khoi he snippets" » "duc khoa he snippets", "luc khoi he snippets", "buoc khoi he snippets", "duc khoi de snippets", "duc khong he 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 khoi he 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 khoi he snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duc khoi he snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duc khoi he snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.