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