Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
lky nang » ly nang, ki nang, ke nang
thanh vi » thanh va, thanh ve, nhanh vi
te sach » toc sach
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
duc gia » quoc gia
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ky nang) or (lky nang)) x ho. hieu van cau duc gia ((thanh vi) OR (hanh vi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky nang) OR (lky nang)) x ho. hieu van cau duc gia ((thanh vi) OR (hanh vi)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky nang) or (lky nang)) x ho. hieu van cau duc gia ((thanh vi) OR (hanh vi)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky nang) or (lky nang)) x ho. hieu van cau duc gia ((thanh vi) OR (hanh vi)) cuu tre*.