Perhaps you should try some spelling variations:
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
thong cong » trong cong, tong cong, thong thong
thang cua » thong cua, hang cua, than cua
tang luan » dung luan
cong san » cong tac
san tran » tan tran, ban tran, dang tran
tran cau » tran chau, toan cau, ran cau

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 (thien hach)) - hanh ((thang cua) or (tang luan)) thong cong san tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien hach)) - hanh ((thang cua) OR (tang luan)) thong cong san tran cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) OR (thien hach)) - hanh ((thang cua) or (tang luan)) thong cong san tran cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) OR (thien hach)) - hanh ((thang cua) or (tang luan)) thong cong san tran cau*.