Perhaps you should try some spelling variations:
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
va thanh » gia thanh, ban thanh, va tinh
vai cua » dai cua, hai cua, lai cua
thuc va » thuc vat, thuc dan, thuc day
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
vi cua » di cua
ve am » va am

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 van nang ((mai hoi) OR (dai hoi)). hieu ve am thuc va thanh ((vi cua) or (vai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach van nang ((mai hoi) OR (dai hoi)). hieu ve am thuc va thanh ((vi cua) OR (vai cua)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach van nang ((mai hoi) OR (dai hoi)). hieu ve am thuc va thanh ((vi cua) or (vai cua)) viet".
• Adding a wildcard symbol may retrieve word variants: so sach van nang ((mai hoi) OR (dai hoi)). hieu ve am thuc va thanh ((vi cua) or (vai cua)) viet*.