Perhaps you should try some spelling variations:
"dong tac cham snippets" » "dong tac code snippets", "cong tac cham snippets", "dong tai cham snippets", "dong bac cham snippets", "dong tac pham snippets", "dong toc cham snippets", "dong tam cham 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 tac cham 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 tac cham snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( dong tac cham snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong tac cham snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.