Perhaps you should try some spelling variations:
phuong trinh » chuong trinh, cong trinh, huong tran
thi phuong » thi truong
hieu lang » chieu sang, hieu quang, nhieu tang
trang cua » tang cua, trung cua, thang cua
tranh cua » doanh cua, manh cua
doi hieu » doi chieu, doc hieu, doi hien
toan cao » toan ban
toan tap » toan ban

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: doi hieu lang - hanh ((trang cua) OR (tranh cua)) thi phuong trinh ((toan cao) OR (toan tap))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - hanh ((trang cua) or (tranh cua)) thi phuong trinh ((toan cao) OR (toan tap))~".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh ((trang cua) or (tranh cua)) thi phuong trinh ((toan cao) OR (toan tap))*.