Perhaps you should try some spelling variations:
cuu thuc » cuu tac
dieu tra » dieu tri, kiem tra
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
sach ky » sac ky, sach ty, sach kem
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
va cuu » va cau, va chu, va huu

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: te ((sach ky) OR (sach y)) nang ma hoi. hieu va cuu thuc van hanh ((dieu tra) OR (dieu cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) or (sach y)) nang ma hoi. hieu va cuu thuc van hanh ((dieu tra) OR (dieu cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sach y)) nang ma hoi. hieu va cuu thuc van hanh ((dieu tra) OR (dieu cua)) tre*.