Perhaps you should try some spelling variations:
dang xay » dang van, van xay
tang tai » hang tai, dung tai, sang tao
van tang » van thang, van trang, van nang
dong xay » cong xay, mong xay, dong xa
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
so sach » bo sach, co sach, hoc sach
so sanh » do sanh
cuc te » cua te, cuc thue, cuc tieu

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: ((so sach) OR (so sanh)) tay ((dong xay) OR (dang xay)) hoi. hieu va cac duc van tang tai cuc te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (so sanh)) tay ((dong xay) OR (dang xay)) hoi. hieu va cac duc van tang tai cuc te~".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (so sanh)) tay ((dong xay) OR (dang xay)) hoi. hieu va cac duc van tang tai cuc te*.