Perhaps you should try some spelling variations:
"van cong code snippets" » "van cong cong snippets", "van cong co snippets", "van cong che snippets", "van dong code snippets", "van phong code snippets", "phan cong code snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug core snippets" » "locating bug code snippets"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"van cong code snippets\") OR (\"dung java java snippets\"))) OR (\"locating bug core snippets\"))~".
• Removing quotes may allow a broader search: (((( van cong code snippets ) OR ( dung java java snippets ))) OR ( locating bug core snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("van cong code snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets"))*.