Perhaps you should try some spelling variations:
"trinh van dan slippers" » "trinh han dan slippers", "trinh quan dan slippers", "trinh toan dan slippers", "trinh van ban slippers", "trinh ban dan slippers", "trinh van dao slippers", "trinh van dan slippery", "trinh van dan 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: (((("trinh van dan slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("trinh van dan slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( trinh van dan slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trinh van dan slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.