Perhaps you should try some spelling variations:
thanh ca » thanh cha, thanh cac, thanh ha
sach ky » sac ky, sach y, sach ty
duoc ma » duoc lam
duoc va » nuoc va, duc va, duong va
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
va lam » van lam, va lap
ma hoi » mai hoi, xa hoi, me hoi
ca cua » co cua

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 ((ma hoi) or (ma hoa)). lieu va lam ((duoc va) OR (duoc ma)) thanh ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang ((ma hoi) OR (ma hoa)). lieu va lam ((duoc va) OR (duoc ma)) thanh ca cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang ((ma hoi) or (ma hoa)). lieu va lam ((duoc va) OR (duoc ma)) thanh ca cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang ((ma hoi) or (ma hoa)). lieu va lam ((duoc va) OR (duoc ma)) thanh ca cua tre*.