Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
vu sach » vu bach, su sach, vu khach
va vanh » va van, va danh, va hanh
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
ve nam » he nam, va nam, te nam
le nam » ly nam, he nam, le na
v nang » va nang, vu nang, van nang
o hai » co hai, so hai, o lai
x hoi » xa hoi, o hoi, x ho

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

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