Perhaps you should try some spelling variations:
nha thuoc » nha nuoc, nhan thuc, nha hoc
thanh de » hanh de, thanh ve, thanh do
ma thanh » mai thanh, va thanh, ha thanh
thuoc ma » hoc ma, duoc ma
hieu van » hieu va, thien van, lieu va
van nha » van nhan, van ha, ban nha
cua tre » cua te, cuu tre, cua triet
sach ly » sach y, sach lo, sach hay
sach ty » sach y, sach tu, sach thu
ma hoi » mai hoi, ma hoa, me hoi
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach ly) or (sach ty)) nang ((ma hoi) OR (xa hoi)). hieu van nha thuoc ma thanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ly) OR (sach ty)) nang ((ma hoi) OR (xa hoi)). hieu van nha thuoc ma thanh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ly) or (sach ty)) nang ((ma hoi) OR (xa hoi)). hieu van nha thuoc ma thanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach ly) or (sach ty)) nang ((ma hoi) OR (xa hoi)). hieu van nha thuoc ma thanh de cua tre*.