Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
hieu cach » hieu cac, chieu sach, hieu ca
dang cong » dung cong
tung cua » trung cua, tuong cua, tang cua
dung cua » dung luan, dung cho
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sach) or (hieu cach)) - thanh ((tung cua) OR (dung cua)) dang cong dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cach)) - thanh ((tung cua) OR (dung cua)) dang cong dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (hieu cach)) - thanh ((tung cua) OR (dung cua)) dang cong dan than cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hieu cach)) - thanh ((tung cua) OR (dung cua)) dang cong dan than cau*.