Perhaps you should try some spelling variations:
"using cao dan slippers" » "using a dan slippers", "using two dan slippers", "using c dan slippers", "using cao dang slippers", "using cao danh slippers", "using cac dan slippers", "using cao dan slippery", "using cao dan grippers"
"hang java java snippets" » "hang 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: (((("using cao dan slippers") or ("hang java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using cao dan slippers") OR ("hang java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using cao dan slippers ) or ( hang java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using cao dan slippers") or ("hang java java snippets"))) or ("locating bug code snippets"))*.