Perhaps you should try some spelling variations:
"dung java java snippets" » "dung va java snippets"
"van hoc cong snippets" » "van hoc co snippets", "van cac cong snippets", "van hoc dung snippets", "van hoa cong snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: "((((\"dung java java snippets\") OR (\"van hoc cong snippets\"))) OR (\"locating bug code snippets\"))~".
• Removing quotes may allow a broader search: (((( dung java java snippets ) OR ( van hoc cong snippets ))) OR ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("dung java java snippets") OR ("van hoc cong snippets"))) OR ("locating bug code snippets"))*.