Perhaps you should try some spelling variations:
thien van » thi van
cach thoi » cac thoi, cach thuc, cach noi
nam thuc » nam thuoc, am thuc, nam thu
sang mai » sang ma, sang tai, lang mai
sach hoi » sach doi, sach moi, hoach hoi
hanh te » hanh tu, hanh ve, hanh de
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
ca viet » va viet, co viet, hoa viet
te ca » te cao, te cua, te cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach hoi) or (cach thoi)) sang mai hoi. ((thien van) or (hieu va)) nam thuc va hanh te ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach hoi) OR (cach thoi)) sang mai hoi. ((thien van) OR (hieu va)) nam thuc va hanh te ca viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach hoi) or (cach thoi)) sang mai hoi. ((thien van) or (hieu va)) nam thuc va hanh te ca viet*.