Perhaps you should try some spelling variations:
phuong doan » phuong loan, phuong hoang, huong dan
dung phuong » dung thuong, bang phuong, dung chung
chieu sang » chieu sach, chieu xanh, hieu lang
doi chieu » doc hieu, doi chi, ho chieu
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
toan cao » toan ban, toan tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doi chieu sang - hanh ((trinh va) OR (trinh ve)) dung phuong doan ((doanh tai) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sang - hanh ((trinh va) OR (trinh ve)) dung phuong doan ((doanh tai) OR (toan cao)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chieu sang - hanh ((trinh va) OR (trinh ve)) dung phuong doan ((doanh tai) or (toan cao))".
• Adding a wildcard symbol may retrieve word variants: doi chieu sang - hanh ((trinh va) OR (trinh ve)) dung phuong doan ((doanh tai) or (toan cao))*.