Perhaps you should try some spelling variations:
"dong tham cach snippets" » "dong tham code snippets", "dong tam cach snippets", "hong tham cach snippets", "dong thap cach snippets", "dong tham canh snippets", "dong nhan cach snippets", "dong pham sach 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 tham cach 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 tham cach snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( dong tham cach snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong tham cach snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.