Perhaps you should try some spelling variations:
"viet trong code snippets" » "viet trung code snippets", "viet thong code snippets", "viet huong code snippets", "viet trong cong snippets", "viet trong co snippets", "viet trong che snippets"
"locating bug core snippets" » "locating bug code snippets"
"using a java snippets" » "using _ java 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: "((((\"viet trong code snippets\") OR (\"using a java snippets\"))) OR (\"locating bug core snippets\"))~".
• Removing quotes may allow a broader search: (((( viet trong code snippets ) OR ( using a java snippets ))) OR ( locating bug core snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("viet trong code snippets") OR ("using a java snippets"))) OR ("locating bug core snippets"))*.