Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
cam truc » cau truc, nam truc, lam truoc
hanh di » hanh vi, hanh de, hang di
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
sach va » sach xa, sach ha, sach dao
sach v » sach y, sach 2, sach vay
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach v) OR (sach va)) nang xa hoi. ((hieu ve) or (hieu va)) cam truc van hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach v) OR (sach va)) nang xa hoi. ((hieu ve) OR (hieu va)) cam truc van hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach v) OR (sach va)) nang xa hoi. ((hieu ve) or (hieu va)) cam truc van hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach v) OR (sach va)) nang xa hoi. ((hieu ve) or (hieu va)) cam truc van hanh di cua tre*.