Perhaps you should try some spelling variations:
nhanh hoi » nhanh hai, nhanh hon, nhanh hoan
va nhanh » va thanh, va hanh, va nhan
hieu van » hieu va, thien van, lieu va
te sach » toc sach
cau duc » cao duc, cau luc, chu duc
cua tre » cua te, cua triet, dua tren
van cau » van dau, van hau, van chat
sach ky » sac ky, sach y, sach ty
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
cuu 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 ((mai hoi) or (dai hoi)). hieu van cau duc va nhanh hoi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((mai hoi) OR (dai hoi)). hieu van cau duc va nhanh hoi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((mai hoi) or (dai hoi)). hieu van cau duc va nhanh hoi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((mai hoi) or (dai hoi)). hieu van cau duc va nhanh hoi ((cua tre) OR (cuu tre))*.