Perhaps you should try some spelling variations:
"dong hieu trinh snippets" » "dong tieu trinh snippets", "dong lieu tinh snippets", "dong tien trinh snippets", "dung hieu trinh snippets", "dong trieu trinh snippets", "doc hieu trinh snippets", "dong hieu trinh slippers"
"using 3d code snippets" » "using 3 code snippets", "using a code snippets", "using _ code snippets", "using cfd code snippets", "using 3d 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 3d code snippets") or ("dong hieu trinh snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using 3d code snippets") OR ("dong hieu trinh snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using 3d code snippets ) or ( dong hieu trinh snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using 3d code snippets") or ("dong hieu trinh snippets"))) or ("locating bug code snippets"))*.