Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, lai hoi, mai doi
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
ve cac » va cac, vien 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: so sach v nang ((mai hoi) or (dai hoi)). hieu ve cac thuc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach v nang ((mai hoi) OR (dai hoi)). hieu ve cac thuc va hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: so sach v nang ((mai hoi) or (dai hoi)). hieu ve cac thuc va hanh vi cua viet*.