Perhaps you should try some spelling variations:
"vi trinh luan slippery" » "vi trinh luat slippery", "vi trinh quan slippery", "vi trinh han slippery", "vi tinh luan slippery", "va trinh luan slippery", "viet trinh luan slippery", "vi trinh luan slippers"
"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: "((((\"vi trinh luan slippery\") OR (\"using java java snippets\"))) OR (\"locating bug code snippets\"))~".
• Removing quotes may allow a broader search: (((( vi trinh luan slippery ) OR ( using java java snippets ))) OR ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("vi trinh luan slippery") OR ("using java java snippets"))) OR ("locating bug code snippets"))*.