Perhaps you should try some spelling variations:
tra nang » thi nang, kha nang, da nang
ban hanh » ban hang
thuc ban » thuoc ban, thuc dan, thu ban
tru nang » tri nang, truc nano, thi nang
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
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) or (su sach)) ((tru nang) or (tra nang)) x hoi. hieu van nam thuc ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ((tru nang) OR (tra nang)) x hoi. hieu van nam thuc ban hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ((tru nang) or (tra nang)) x hoi. hieu van nam thuc ban hanh vi cua tre*.