Perhaps you should try some spelling variations:
theo hoc » theo hop, te hoc, cho hoc
thao hoc » thai hoc, than hoc, thao khoa
anh tang » anh bang, anh dang, anh nang
cua dung » cua dang, qua dung, cua rung
cua dong » chua dong, cua cong, cua dang
cong tan » cong tac, cong san, cong thanh
tran cao » toan cao, tran chau, trang cho

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: ((theo hoc) OR (thao hoc)) sach - anh tang ((cua dung) OR (cua dong)) cong tan tran cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo hoc) or (thao hoc)) sach - anh tang ((cua dung) OR (cua dong)) cong tan tran cao~".
• Adding a wildcard symbol may retrieve word variants: ((theo hoc) or (thao hoc)) sach - anh tang ((cua dung) OR (cua dong)) cong tan tran cao*.