Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
thanh ve » hanh ve, thanh va, thanh vien
duc van » duc va, duc tan, duc manh
vuc van » luc van, thuc van, chuc van
hieu va » lieu va, hieu qua
vu nang » vuc nang, va nang, vu dang
sach vu » sach va, sach tu, sach uu
su tien » su kien, su hien, tu tieng
va cam » va cham, va cac, va cao
o hai » co hai, so hai, o lai
x hoi » xa hoi, o hoi, x ho
ve su » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach vu nang ((x hoi) or (o hai)). hieu va cam ((vuc van) or (duc van)) thanh ve su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach vu nang ((x hoi) OR (o hai)). hieu va cam ((vuc van) OR (duc van)) thanh ve su tien.
• Adding a wildcard symbol may retrieve word variants: thu sach vu nang ((x hoi) or (o hai)). hieu va cam ((vuc van) or (duc van)) thanh ve su tien*.