Perhaps you should try some spelling variations:
"using data core snippets" » "using java core snippets", "using sat core snippets", "missing data core snippets"
"ngan sach han snippets" » "ngan sach tham snippets", "ngan sach danh snippets", "ngan sach nang snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code 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 data core snippets\") OR (\"ngan sach han snippets\"))) OR (\"locating bug code snippets\"))~".
• Removing quotes may allow a broader search: (((( using data core snippets ) OR ( ngan sach han snippets ))) OR ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("using data core snippets") OR ("ngan sach han snippets"))) OR ("locating bug code snippets"))*.