Perhaps you should try some spelling variations:
"dang nhat code snippets" » "dang nhat de snippets", "dang nhat co snippets", "dung nhan code snippets", "dung nha code snippets"
"cong trinh java slippers" » "cong trinh java slippery", "cong trinh java grippers"
"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: (((("cong trinh java slippers") or ("dang nhat code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("cong trinh java slippers") OR ("dang nhat code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong trinh java slippers ) or ( dang nhat code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong trinh java slippers") or ("dang nhat code snippets"))) or ("locating bug code snippets"))*.