Perhaps you should try some spelling variations:
"dung danh trac snippets" » "dung doanh trac snippets", "dung dan trac snippets", "dung dang trac snippets", "dung anh trac snippets", "dung dang tran snippets", "dung danh thuc snippets"
"using a core snippets" » "using _ core snippets", "using a care snippets", "using a corn 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.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("using a core snippets") or ("dung danh trac snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using a core snippets") OR ("dung danh trac snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using a core snippets ) or ( dung danh trac snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using a core snippets") or ("dung danh trac snippets"))) or ("locating bug code snippets"))*.