Perhaps you should try some spelling variations:
dung phuong » dung thuong, bang phuong, dung chung
phuong dan » phuong danh, phuong doan, huong dan
hieu xanh » chieu xanh, hieu manh, hieu nganh
trinh van » trinh quan, trinh toan, dinh van
trinh han » trinh quan
doc hieu » toc thieu, hoc thieu, hoc hien
dan toan » van toan, dan than, manh toan
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: doc hieu xanh - canh ((trinh van) OR (trinh han)) dung phuong dan toan ban~.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh ((trinh van) or (trinh han)) dung phuong dan toan ban*.