Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dung sai » dung tai, dung va, dung dat
lam thuc » lam thuoc, am thuc, nam thuc
tu sach » thu sach, su sach, te sach
nang co » nang cao, nang doc, nang noi
hieu va » hieu qua
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
va dung » van dung, va duong, vat dung
co hoi » co hoc, co loi
thiet » thieu

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 ky nang co hoi. ((hieu va) OR (lieu va)) lam thuc va dung sai ((cua triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang co hoi. ((hieu va) OR (lieu va)) lam thuc va dung sai ((cua triet) OR (va thiet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang co hoi. ((hieu va) OR (lieu va)) lam thuc va dung sai ((cua triet) or (va thiet))*".