Perhaps you should try some spelling variations:
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
thuc va » thuc dan, thuc day
vi cua » vai cua, di cua
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sac ky nang ma hoi. ((hieu ve) OR (hieu va)) nam ((thuc va) or (thuc vat)) hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky nang ma hoi. ((hieu ve) OR (hieu va)) nam ((thuc va) OR (thuc vat)) hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sac ky nang ma hoi. ((hieu ve) OR (hieu va)) nam ((thuc va) or (thuc vat)) hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: vu sac ky nang ma hoi. ((hieu ve) OR (hieu va)) nam ((thuc va) or (thuc vat)) hanh vi cua te*.