Perhaps you should try some spelling variations:
"van thinh doc snippets" » "van thanh doc snippets", "van chinh doc snippets", "van minh doc snippets", "van trinh doc snippets", "van thinh duc snippets", "van thinh doan 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"

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 thinh doc snippets\") OR (\"dung java java snippets\"))) OR (\"locating bug code snippets\"))~".
• Removing quotes may allow a broader search: (((( van thinh doc snippets ) OR ( dung java java snippets ))) OR ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("van thinh doc snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets"))*.