Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
lam thuc » lam thuoc, am thuc, nam thuc
va triet » va thiet, ve triet, cua triet
tinh vai » tinh va, tinh hai, tinh bai
va tinh » may tinh
thuc va » thuc vat, thuc dan, thuc day
te sach » toc sach
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
va lam » van lam, va lap

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((nang ma) OR (tang ma)) hoi. hieu va lam thuc va tinh vai ((va triet) or (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang ma) OR (tang ma)) hoi. hieu va lam thuc va tinh vai ((va triet) OR (va trien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((nang ma) OR (tang ma)) hoi. hieu va lam thuc va tinh vai ((va triet) or (va trien))".
• Adding a wildcard symbol may retrieve word variants: te sach y ((nang ma) OR (tang ma)) hoi. hieu va lam thuc va tinh vai ((va triet) or (va trien))*.