Perhaps you should try some spelling variations:
"dung sach sio2 snippets" » "duong sach sio2 snippets", "dung sai sio2 snippets", "dung cac sio2 snippets", "dung sic sio2 snippets", "dung sach sio2 slippers"
"python using a snippets" » "python using a slippers"
"locating bug code snippets" » "locating bug code slippers", "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 sach sio2 snippets") or ("python using a snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung sach sio2 snippets") OR ("python using a snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung sach sio2 snippets ) or ( python using a snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung sach sio2 snippets") or ("python using a snippets"))) or ("locating bug code snippets"))*.