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