Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
te sach » toc sach
tai cua » thai cua, tai cuc, tri cua
tai cuu » tai cuc, tai buu, thai cua
xa hanh » xa thanh, xa khanh, va hanh
thuc xa » thuc xay, tuc xa, thuc va
sach ky » sac ky, sach y, sach ty
hieu va » lieu va
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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 ky nang ma hoi. ((hieu va) or (hieu qua)) nam thuc xa hanh ((tai cuu) OR (tai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ma hoi. ((hieu va) OR (hieu qua)) nam thuc xa hanh ((tai cuu) OR (tai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ma hoi. ((hieu va) or (hieu qua)) nam thuc xa hanh ((tai cuu) OR (tai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ma hoi. ((hieu va) or (hieu qua)) nam thuc xa hanh ((tai cuu) OR (tai cua)) tre*.