Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
hanh di » hanh vi, hanh de, hang di
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
va lam » van lam
va lap » va dap

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 lang xa hoi. hieu ((va lam) OR (va lap)) thuc day hanh di ((cua triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu ((va lam) OR (va lap)) thuc day hanh di ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. hieu ((va lam) OR (va lap)) thuc day hanh di ((cua triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu ((va lam) OR (va lap)) thuc day hanh di ((cua triet) or (su triet))*.