Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
hieu van » hieu va, thien van, lieu va
thuoc ma » hoc ma, duoc ma
te sach » toc sach
ty lang » tay lang, ty xang, tu lang
ty hang » ly hang, ty xang, thi hang
ma hang » mat hang, mua hang, va hang
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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 ((ty lang) or (ty hang)) xa hoi. hieu van nam thuoc ma hang va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty lang) OR (ty hang)) xa hoi. hieu van nam thuoc ma hang va cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ((ty lang) or (ty hang)) xa hoi. hieu van nam thuoc ma hang va cua tre*.