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