Perhaps you should try some spelling variations:
"duong van cuc snippets" » "duong va cuc snippets", "luong va cuc snippets", "dang van cuc snippets", "duong van duc snippets", "duong van luc snippets", "duong van cu 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 van cuc 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 van cuc snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duong van cuc snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duong van cuc snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.