Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
lam duc » lam duoc, pham duc, nam duoc
van lam » van nam
cuu tre » cua tre, cau tren, cau treo
mai hoi » mai khoi, dai hoi, lai hoi
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ((ky tang) or (ky dang)) mai hoi. hieu van lam duc va ((hanh tai) or (hanh vi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ((ky tang) OR (ky dang)) mai hoi. hieu van lam duc va ((hanh tai) OR (hanh vi)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sac ((ky tang) or (ky dang)) mai hoi. hieu van lam duc va ((hanh tai) or (hanh vi)) cuu tre*.