Perhaps you should try some spelling variations:
nhung phuong » dung phuong, nhu phuong, truong phuong
phuong tinh » phuong trinh, phuong binh, khuong tinh
chieu sang » chieu sach, chieu xanh, hieu lang
cua nhung » va nhung
ho chieu » theo chieu, hoc thieu, doi chieu
lanh ban » lanh bang, lang ban, doanh ban
toan tai » toan tap, doanh tai, toan cao
toan ban » van ban
ban cua » ban quan

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: ho chieu sang - lanh ban cua nhung phuong tinh ((toan tai) OR (toan ban))~.
• Adding a wildcard symbol may retrieve word variants: ho chieu sang - lanh ban cua nhung phuong tinh ((toan tai) or (toan ban))*.