Perhaps you should try some spelling variations:
"van dung code snippets" » "van dung cong snippets", "van dung co snippets", "van dung de snippets", "van dong code snippets", "xay dung code snippets", "tin dung code snippets"
"using c core snippets" » "using lc core snippets", "using a core snippets", "using _ core snippets"
"locating bug code snippets" » "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 c core snippets") or ("van dung code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using c core snippets") OR ("van dung code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using c core snippets ) or ( van dung code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using c core snippets") or ("van dung code snippets"))) or ("locating bug code snippets"))*.