Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
trung va » truong va, trang va, trung ha
ba trung » tai trung, nam trung, do trung
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
sach v » sach va, sach y, sach vay
sach 2 » sach y

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: su ((sach v) OR (sach 2)) nang xa hoi. ((hieu ve) OR (hieu va)) ba trung va hanh dai cua vat~.
• Adding a wildcard symbol may retrieve word variants: su ((sach v) or (sach 2)) nang xa hoi. ((hieu ve) or (hieu va)) ba trung va hanh dai cua vat*.