Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
quan thanh » van thanh
thang cong » thanh cong, thang long, thong cong
hieu cach » hieu cac, chieu sach, hieu ca
ban thanh » ban hanh, ban hang
cong san » cong tac
san khan » san khau, san khac, san phan
khan ap » khan cap, han ap, khan dam

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: toc ((thieu sach) OR (hieu cach)) - thanh ((quan thanh) OR (ban thanh)) thang cong san khan ap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((thieu sach) or (hieu cach)) - thanh ((quan thanh) OR (ban thanh)) thang cong san khan ap~".
• Adding a wildcard symbol may retrieve word variants: toc ((thieu sach) or (hieu cach)) - thanh ((quan thanh) OR (ban thanh)) thang cong san khan ap*.