Perhaps you should try some spelling variations:
phuong tinh » phuong trinh, phuong binh, khuong tinh
chieu sach » chinh sach, chiet tach, chieu xanh
chieu sang » chieu xanh, hieu lang, nhieu tang
manh hung » anh huong
hung cua » huong cua, chung cua, khung cua
cua bang » chua bang, cua ban, cua dang
toan cao » toan tap
toan ban » van 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: theo ((chieu sach) OR (chieu sang)) - manh hung cua bang phuong tinh ((toan cao) OR (toan ban))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) or (chieu sang)) - manh hung cua bang phuong tinh ((toan cao) OR (toan ban))~".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (chieu sang)) - manh hung cua bang phuong tinh ((toan cao) OR (toan ban))*.