Perhaps you should try some spelling variations:
trinh quang » trinh quan, tranh quang, trinh dung
dung phuong » dung thuong, bang phuong, dung chung
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
phuong van » phung van, phong van, phuong lan
van toan » van tuan, van tan, van thanh
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: hoc ((chieu xanh) OR (chieu sang)) - hanh ((trinh quang) or (tinh quang)) dung phuong van toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu xanh) OR (chieu sang)) - hanh ((trinh quang) OR (tinh quang)) dung phuong van toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu xanh) OR (chieu sang)) - hanh ((trinh quang) or (tinh quang)) dung phuong van toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) OR (chieu sang)) - hanh ((trinh quang) or (tinh quang)) dung phuong van toan cao*.