Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thanh van » thanh san, thanh toan, thanh phan
hieu cua » hieu qua, dieu cua, bieu cua
thuoc va » thuc va, thuoc ma, thuong va
tu sach » thu sach, su sach, te sach
hanh va » hang va, hanh vi
cua nam » cua tam, cua ngan, cua nhan
sach ly » sach y, sach lo, sach ty
ly tang » le tang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ly tang ((ma hoi) or (ma hoa)). hieu cua nam thuoc va ((thanh van) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly tang ((ma hoi) OR (ma hoa)). hieu cua nam thuoc va ((thanh van) OR (hanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ly tang ((ma hoi) or (ma hoa)). hieu cua nam thuoc va ((thanh van) or (hanh va)) cua tre*.