Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"dung khoa o2 snippets" » "dung cho o2 snippets", "dung khoa hoc snippets", "dung khoa doi snippets", "dung khoa hoi 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: (((("dung khoa o2 snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung khoa o2 snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung khoa o2 snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung khoa o2 snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.