Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
tang ma » mang may, tang van
va hanh » van hanh, va thanh, va danh
vi su » va su, ve su, ki su

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 xa) or (tang ma)) hoi. hieu van pham duc va hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (tang ma)) hoi. hieu van pham duc va hanh vi su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (tang ma)) hoi. hieu van pham duc va hanh vi su triet*.