Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
ban thanh » ban hanh, ban hang
thuc ban » thuoc ban, thuc dan, thu ban
nam thuc » nam thuoc, am thuc, nam thu
tai cuu » tai buu, tai cua, thai cua
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
va nam » van nam, ha nam, va nay

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: thuat sach ty ((nang ma) OR (nang x)) hoi. hieu va nam thuc ban thanh ((tai cuu) OR (tai cuc)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ty ((nang ma) or (nang x)) hoi. hieu va nam thuc ban thanh ((tai cuu) OR (tai cuc)) tre~".
• Adding a wildcard symbol may retrieve word variants: thuat sach ty ((nang ma) or (nang x)) hoi. hieu va nam thuc ban thanh ((tai cuu) OR (tai cuc)) tre*.