Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
thanh cham » thanh pham, hanh cham, thanh cha
dat quang » dau quang, chat quang, dang quang
hoc thanh » hoc nhanh, hoan thanh, hoc phan
van dung » van dong, xay dung, tin dung
cong hoc » dong hoc, cong hoa, cong coc

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 ((dat quang) or (van dung)) cong hoc thanh cham~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - thanh cong ((dat quang) OR (van dung)) cong hoc thanh cham.
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - thanh cong ((dat quang) or (van dung)) cong hoc thanh cham*.