Perhaps you should try some spelling variations:
thien van » thi van
hanh duoi » hanh duoc, hanh noi, gach duoi
thu sach » thuat sach, thuoc sach, thu hoach
cam thuc » am thuc, nam thuc, cam thu
tu sach » su sach, te sach, tu cach
duoi ca » doi ca, cuoi cua, nuoi cay
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
ca viet » va viet, co viet, hoa viet
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
ma hoi » mai hoi, xa hoi, ma hoa

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) or (thu sach)) ky tang ma hoi. ((hieu va) or (thien van)) cam thuc va hanh duoi ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky tang ma hoi. ((hieu va) OR (thien van)) cam thuc va hanh duoi ca viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky tang ma hoi. ((hieu va) or (thien van)) cam thuc va hanh duoi ca viet*.