Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
thuat chan » thuat toan, thuat san
dang cong » dung cong
cong lang » cong vang, cong luong, cong quang
chat ran » chat ban, chat va
cong su » cong suc, cong sua, cong cu
su dang » su dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc thieu sach - thanh cong su dang cong lang ((chat ran) or (thuat chan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - thanh cong su dang cong lang ((chat ran) OR (thuat chan)).
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - thanh cong su dang cong lang ((chat ran) or (thuat chan))*.