Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
hanh thai » nhanh thai, hinh thai, hanh tai
va triet » va thiet, va trien, ve triet
ve pham » vi pham, v pham, ve phan
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mang xa » lang xa, mang may, dang xay
hieu ve » hieu va, hieu van

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 ((mang xa) or (nang x)) hoi. hieu ve pham duc va hanh thai ((cua triet) OR (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((mang xa) OR (nang x)) hoi. hieu ve pham duc va hanh thai ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((mang xa) or (nang x)) hoi. hieu ve pham duc va hanh thai ((cua triet) OR (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((mang xa) or (nang x)) hoi. hieu ve pham duc va hanh thai ((cua triet) OR (va triet))*.