Perhaps you should try some spelling variations:
"trong tranh do snippets" » "trong thanh do snippets", "trong trang do snippets", "trong nganh do snippets", "trong trinh do snippets"
"data using java snippets" » "data using data 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: (((("trong tranh do snippets") or ("data using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("trong tranh do snippets") OR ("data using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( trong tranh do snippets ) or ( data using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trong tranh do snippets") or ("data using java snippets"))) or ("locating bug code snippets"))*.