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