Perhaps you should try some spelling variations:
"dong chan cong snippets" » "dong chan code snippets", "dong chuan cong snippets", "jong chan cong snippets", "dong chen cong snippets", "dong phan cong snippets", "dong chan hong snippets", "dong chat cong snippets"
"locating bug core snippets" » "locating bug code snippets"
"dung java java snippets" » "dung va java 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 chan cong snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dong chan cong snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( dong chan cong snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong chan cong snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.