Perhaps you should try some spelling variations:
"trong khoa code snippets" » "truong khoa code snippets", "tuong khoa code snippets", "trung khoa code snippets", "trong khoa cong snippets", "trong khoa co snippets", "trong khoa de snippets", "trong khoa code slippers"
"using a code snippets" » "using a code slippers"
"locating bug code snippets" » "locating bug code slippers", "locating bung code snippets", "locating bugs code 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: (((("using a code snippets") or ("trong khoa code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using a code snippets") OR ("trong khoa code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using a code snippets ) or ( trong khoa code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using a code snippets") or ("trong khoa code snippets"))) or ("locating bug code snippets"))*.