Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, hoc sach, cuoc cach
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 va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
y sang » _ sang, duy sang
ve cau » va cau, ve cac, le cau
ke cau » ket cau
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: nuoc sach y sang ((mai hoi) or (mai khoi)). hieu ((ve cau) OR (ke cau)) truc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nuoc sach y sang ((mai hoi) OR (mai khoi)). hieu ((ve cau) OR (ke cau)) truc va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "nuoc sach y sang ((mai hoi) or (mai khoi)). hieu ((ve cau) OR (ke cau)) truc va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: nuoc sach y sang ((mai hoi) or (mai khoi)). hieu ((ve cau) OR (ke cau)) truc va hanh vi cua viet*.