Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh hai » thanh hai, nhanh hai, hang hai
trung va » truong va, trang va, trung ha
hai cua » thai cua, dai cua, hoi cua
truc va » thuc va, thuc vat
so sinh » so sanh, so tinh, cho sinh
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
sinh v » sinh va, sinh y, sinh vat
ve cam » ve cham, ve cac, va cam

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

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