Perhaps you should try some spelling variations:
"tra trinh luat slippers" » "qua trinh luat slippers", "tra trinh luan slippers", "tra trinh xuat slippers", "tra trinh luat slippery", "tra trinh luat grippers"
"dung java java snippets" » "dung va java snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: (((("tra trinh luat slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("tra trinh luat slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( tra trinh luat slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("tra trinh luat slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.