Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"2015 den cua snippets" » "21 den cua snippets", "2015 dien cua snippets", "2015 de cua snippets", "2015 dan cua snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core snippets"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("2015 den cua snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("2015 den cua snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( 2015 den cua snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("2015 den cua snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.