Perhaps you should try some spelling variations:
dang thuoc » dung thuoc
ban thuoc » cay thuoc, nam thuoc, va thuoc
hieu viec » nhieu viec, hieu ve, sieu viet
danh tu » anh tu, doanh thu
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
sac ky » cac ky, sai ky
tu cua » hu cua, vu cua
so sac » so sach, so dac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: so sac ky ((nang xa) OR (nang ma)) hoi. hieu viec ((ban thuoc) OR (dang thuoc)) va danh tu cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sac ky ((nang xa) or (nang ma)) hoi. hieu viec ((ban thuoc) OR (dang thuoc)) va danh tu cua tre~".
• Adding a wildcard symbol may retrieve word variants: so sac ky ((nang xa) or (nang ma)) hoi. hieu viec ((ban thuoc) OR (dang thuoc)) va danh tu cua tre*.