Perhaps you should try some spelling variations:
cuoc sach » cuoc cach, cuon sach, nuoc sach
mai khoi » mai khoa, tai khoa, cac khoi
cua viet » ca viet, hoa viet, cua vat
mai hoi » dai hoi, lai hoi, mai doi
truc va » thuc vat, trung va
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
y sang » _ sang, duy sang
ve cau » ke cau, va cau, ve cac
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: cuoc sach y sang ((mai hoi) or (mai khoi)). hieu ve cau ((truc va) OR (thuc va)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: cuoc sach y sang ((mai hoi) OR (mai khoi)). hieu ve cau ((truc va) OR (thuc va)) hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "cuoc sach y sang ((mai hoi) or (mai khoi)). hieu ve cau ((truc va) OR (thuc va)) hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: cuoc sach y sang ((mai hoi) or (mai khoi)). hieu ve cau ((truc va) OR (thuc va)) hanh vi cua viet*.