Perhaps you should try some spelling variations:
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
nang mai » nang ma, nang tai, lang mai
cam thuc » am thuc, nam thuc, cam thu
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
ve cam » ve cham, ve cac, va cam
vi 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 van nang mai hoi. hieu ve cam thuc va hanh ((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. hieu ve cam thuc va hanh ((vi cua) OR (vai cua)) viet.
• Adding a wildcard symbol may retrieve word variants: so sach van nang mai hoi. hieu ve cam thuc va hanh ((vi cua) or (vai cua)) viet*.