Perhaps you should try some spelling variations:
vat trang » vat trong, van trang, nhat trang
thuoc sai » thuoc tai, thuoc san, thuoc sach
cau thuc » cau truc, cuu thuc, can thuc
va trang » va trung, va thanh, va nang
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
sai ky » sac ky
ma hoi » mai hoi, xa hoi, ma hoa
va cau » van cau, va cac, va dau
vai va » mai va, dai va, hai va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sai ky nang ma hoi. hieu va cau thuc ((vat trang) or (va trang)) vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sai ky nang ma hoi. hieu va cau thuc ((vat trang) OR (va trang)) vai va thiet.
• Adding a wildcard symbol may retrieve word variants: thuoc sai ky nang ma hoi. hieu va cau thuc ((vat trang) or (va trang)) vai va thiet*.