Perhaps you should try some spelling variations:
"cong doi canh snippets" » "cong doi code snippets", "vong doi canh snippets", "cong dot canh snippets", "cong goi canh snippets", "cong doi hanh snippets", "cong boi canh snippets", "cong do canh 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: (((("cong doi canh snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("cong doi canh snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( cong doi canh snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong doi canh snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.