Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
trung va » truong va, trang va, trung ha
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap
luan » quan, lan

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 ((toc sach) OR (hoc sach)) - thanh ((trung va) OR (luan van)) nhung cong dan toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((toc sach) OR (hoc sach)) - thanh ((trung va) or (luan van)) nhung cong dan toan cao~".
• Adding a wildcard symbol may retrieve word variants: theo ((toc sach) OR (hoc sach)) - thanh ((trung va) or (luan van)) nhung cong dan toan cao*.