Perhaps you should try some spelling variations:
"duong quang li snippets" » "dung quang li snippets", "luong quang li snippets", "duong qua li snippets", "duong quan li snippets", "duong quang le snippets", "duong guang li snippets"
"using java code slippers" » "using data code slippers"
"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 java code slippers") or ("duong quang li snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using java code slippers") OR ("duong quang li snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using java code slippers ) or ( duong quang li snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using java code slippers") or ("duong quang li snippets"))) or ("locating bug code snippets"))*.