Perhaps you should try some spelling variations:
nhung phuong » dung phuong, nhu phuong, truong phuong
phuong dan » phuong danh, phuong doan, huong dan
hieu sach » chieu sach, hieu cach, hieu cac
dien sach » dien anh
trung cap » truong cao, trung tam
manh cua » doanh cua, ban cua
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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 sach) OR (dien sach)) - hanh ((trung cap) OR (manh cua)) nhung phuong dan toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) OR (dien sach)) - hanh ((trung cap) or (manh cua)) nhung phuong dan toan cau~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) OR (dien sach)) - hanh ((trung cap) or (manh cua)) nhung phuong dan toan cau*.