Perhaps you should try some spelling variations:
"dong trien code snippets" » "dong trien cong snippets", "dong trien con snippets", "dong trieu code snippets", "dong tien code snippets", "dong tren code snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug code slippers" » "locating bung code slippers", "locating bugs code slippers"

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: (((("dung java java snippets") or ("dong trien code snippets"))) or ("locating bug code slippers"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung java java snippets") OR ("dong trien code snippets"))) OR ("locating bug code slippers")).
• Removing quotes may allow a broader search: (((( dung java java snippets ) or ( dong trien code snippets ))) or ( locating bug code slippers )).
• Adding a wildcard symbol may retrieve word variants: (((("dung java java snippets") or ("dong trien code snippets"))) or ("locating bug code slippers"))*.