Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
van nhan » van phan, van thanh, danh nhan
te sach » toc sach
cau duc » cao duc, cau luc, chu duc
hoi cua » hoi chuc
va nhan » ca nhan, va phan, va nha
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
dai hoi » dai hoc, dai hai, dai moi
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau

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 khoi) or (dai hoi)). hieu va cau duc ((va nhan) OR (van nhan)) hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((mai khoi) OR (dai hoi)). hieu va cau duc ((va nhan) OR (van nhan)) hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((mai khoi) or (dai hoi)). hieu va cau duc ((va nhan) OR (van nhan)) hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((mai khoi) or (dai hoi)). hieu va cau duc ((va nhan) OR (van nhan)) hoi cua tre*.