Perhaps you should try some spelling variations:
"duong cao code snippets" » "duong co code snippets", "duong dao code snippets", "duong cac code snippets", "duong cao cong snippets", "duong cao de snippets", "duong cfd code snippets", "duong cao code slippers"
"van trinh java snippets" » "van thinh java snippets", "van tinh java snippets", "dan trinh java snippets", "van trinh java 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: (((("duong cao code snippets") or ("van trinh java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("duong cao code snippets") OR ("van trinh java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duong cao code snippets ) or ( van trinh java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duong cao code snippets") or ("van trinh java snippets"))) or ("locating bug code snippets"))*.