Perhaps you should try some spelling variations:
"dong duc cuong snippets" » "dong dai cuong snippets", "dong duc hung snippets", "duong duc cuong snippets", "dong duoc cuong snippets", "dong luc cuong snippets"
"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: (((("dong duc cuong snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dong duc cuong snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dong duc cuong snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong duc cuong snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.