Perhaps you should try some spelling variations:
manh trung » manh tung, thanh trung, manh hung
chieu sach » chinh sach, chiet tach, chieu sang
theo sach » thuoc sach, te sach, theo lich
trung cua » truong cua, trung tuan, trung cap
cong cong » trong cong, dung cong, dang cong
tan tai » toan tai, tang tai, tuan tai
tai cao » thai cao, tao cao, tai sao

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