Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
trung va » truong va, trang va, trung ha
truc va » thuc va, thuc vat
ca viet » va viet, co viet, hoa viet
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
sinh y » sinh ly
vi ca » vit ca, li ca, va ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: cho sinh y nang ma hoi. ((hieu ve) OR (hieu van)) cham ((truc va) or (trung va)) hanh vi ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: cho sinh y nang ma hoi. ((hieu ve) OR (hieu van)) cham ((truc va) OR (trung va)) hanh vi ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "cho sinh y nang ma hoi. ((hieu ve) OR (hieu van)) cham ((truc va) or (trung va)) hanh vi ca viet".
• Adding a wildcard symbol may retrieve word variants: cho sinh y nang ma hoi. ((hieu ve) OR (hieu van)) cham ((truc va) or (trung va)) hanh vi ca viet*.