Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
thanh tung » thanh cong
hieu cach » hieu cac, chieu sach, hieu ca
lang cong » dang cong, bang cong, hang cong
cong dan » cong san, cong tan, huong dan
than cap » thanh lap, thanh cac, than cua
khan cap » khan ap, khoan cam, phan cac
tung va » trung va, tuong va, dung va
va lang » va nang, hoa lang

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 va lang cong dan ((than cap) OR (khan cap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cach)) - thanh tung va lang cong dan ((than cap) OR (khan cap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (hieu cach)) - thanh tung va lang cong dan ((than cap) OR (khan cap))".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hieu cach)) - thanh tung va lang cong dan ((than cap) OR (khan cap))*.