Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
nhung cong » dung cong, thong cong, hang cong
hieu cach » hieu cac, chieu sach, hieu ca
trung cua » truong cua, trung tuan, dung cua
trung cap » truong cao, trung tam
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
toan tap » toan ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cach)) - manh ((trung cua) OR (trung cap)) nhung cong van toan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (hieu cach)) - manh ((trung cua) OR (trung cap)) nhung cong van toan tap~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hieu cach)) - manh ((trung cua) OR (trung cap)) nhung cong van toan tap*.