Perhaps you should try some spelling variations:
"van cao sio2 snippets" » "van bao sio2 snippets", "van cao son snippets", "van cao so snippets", "van dao sio2 snippets", "van cau sio2 snippets", "van cao 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: (((("van cao 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: (((("van cao sio2 snippets") OR ("python using a snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van cao sio2 snippets ) or ( python using a snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van cao sio2 snippets") or ("python using a snippets"))) or ("locating bug code snippets"))*.