Perhaps you should try some spelling variations:
"duong tan cong snippets" » "duong tuan cong snippets", "duong van cong snippets", "duong tai cong snippets", "duong tan cuong snippets", "duong tran cong snippets", "duong toan cong snippets"
"hang java java snippets" » "hang 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 tan cong snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("duong tan cong snippets") OR ("hang java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duong tan cong snippets ) or ( hang java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duong tan cong snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))*.