Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nam xua » nam cua, nam mua, nam qua
xua ban » xuat ban, cua ban, qua ban
ban anh » ban hanh, ban banh, ban danh
cua tre » cua te, cuu tre, cua triet
anh ve » hanh ve, anh va, anh viet
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: tu sach ky nang x hoi. hieu van nam xua ban anh ve ((dua tren) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu van nam xua ban anh ve ((dua tren) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van nam xua ban anh ve ((dua tren) or (cua tre))*.