Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
duoc may » duoc ma, hoc may, duoc lam
tinh cao » tinh lao, tinh chat, tinh cach
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
va luat » va thuat, vay luan, cua luat
cao cua » ca cua, co cua, cau cua
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: so sach ky nang ((xa hoi) or (mai khoi)). lieu va luat ((duoc may) or (duoc ly)) tinh cao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang ((xa hoi) OR (mai khoi)). lieu va luat ((duoc may) OR (duoc ly)) tinh cao cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang ((xa hoi) or (mai khoi)). lieu va luat ((duoc may) or (duoc ly)) tinh cao cua tre*.