Perhaps you should try some spelling variations:
"vi trung hoc grippers" » "vi trung soft grippers", "vi trung quoc grippers", "va trung hoc grippers", "viet trung hoc grippers", "vien trung hoc grippers"
"using java java snippets" » "using data java snippets", "using java java slippers"
"locating bug code snippets" » "locating bug code slippers", "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: "((((\"using java java snippets\") OR (\"vi trung hoc grippers\"))) OR (\"locating bug code snippets\"))~".
• Removing quotes may allow a broader search: (((( using java java snippets ) OR ( vi trung hoc grippers ))) OR ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("using java java snippets") OR ("vi trung hoc grippers"))) OR ("locating bug code snippets"))*.