Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
ve triet » va trien, su triet
nang doc » nang luc
thuc va » thuc vat, thuc dan, thuc day
dan vai » dan va, dan tai, dan vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang co » nang cao, nang noi, nang hoc
va dan » ca dan, va dao, va dau
va am » va lam, 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 doc)) loi. hieu va am thuc va dan vai ((cua triet) OR (ve triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang co) OR (nang doc)) loi. hieu va am thuc va dan vai ((cua triet) or (ve triet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang co) OR (nang doc)) loi. hieu va am thuc va dan vai ((cua triet) or (ve triet))*.