Perhaps you should try some spelling variations:
"son duong thi snippets" » "song duong thi snippets", "con duong thi snippets", "soi duong thi snippets", "son luong thi snippets", "son dang thi snippets", "son duong thi 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: (((("son duong thi snippets") or ("python using a snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("son duong thi snippets") OR ("python using a snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( son duong thi snippets ) or ( python using a snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("son duong thi snippets") or ("python using a snippets"))) or ("locating bug code snippets"))*.