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