Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
nang noi » nang doc
dan vai » dan va, dan tai, dan vat
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
nang co » nang cao, nang doc, nang hoc
va lam » van lam, va lap
va dan » ca dan, va dao, va dau
vai va » mai va, dai va, hai va
va am » va cam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang co) OR (nang noi)) hoi. hieu ((va am) OR (va lam)) thuc va dan vai va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang co) or (nang noi)) hoi. hieu ((va am) OR (va lam)) thuc va dan vai va triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang co) or (nang noi)) hoi. hieu ((va am) OR (va lam)) thuc va dan vai va triet*.