Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
cong dang » cong dong, cong dung, cong danh
trang va » hang va
tran van » luan van
cong dan » cong san, cong tan, huong dan
than cau » toan cau, phan cau, than cap

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 - hanh ((trang va) OR (tran van)) phuong ((cong dan) OR (cong dang)) than cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - hanh ((trang va) OR (tran van)) phuong ((cong dan) or (cong dang)) than cau~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh ((trang va) OR (tran van)) phuong ((cong dan) or (cong dang)) than cau*.