Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
sach van » sach han, bach van, cach van
va thanh » gia thanh, ban thanh, va tinh
nam thuc » nam thuoc, am thuc, nam thu
thuc va » thuc vat, thuc dan, thuc day
hieu he » hieu ve, hiem he, hieu le
lai roi » lai hoi, loi roi
mai hoi » mai khoi, dai hoi, lai hoi
sach va » sach xa, sach ha, sach dao
vai hoa » van hoa, va hoa, dai hoa
he nam » ha nam, nghe nam

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) OR (sach va)) nang ((mai hoi) or (lai roi)). hieu he nam thuc va thanh vai hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach van) OR (sach va)) nang ((mai hoi) OR (lai roi)). hieu he nam thuc va thanh vai hoa viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach van) OR (sach va)) nang ((mai hoi) or (lai roi)). hieu he nam thuc va thanh vai hoa viet*".