Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh tai, hanh van
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
hanh va » hang va, hanh vi
duc ban » duc tan, duc van, dua ban
lam duc » lam duoc, pham duc, nam duoc
van lam » van nam
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
cua tre » cua te, cuu tre, cua triet

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 lang) OR (ky tang)) xa hoi. hieu van lam duc ban ((hanh vai) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky tang)) xa hoi. hieu van lam duc ban ((hanh vai) OR (hanh va)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) OR (ky tang)) xa hoi. hieu van lam duc ban ((hanh vai) or (hanh va)) cua tre*".