Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
va thanh » gia thanh, ban thanh, va tinh
va hanh » van hanh, va danh, ban hanh
ve phan » va phan, ke phan, ve phat
sach ty » sach y, sach tu, sach thu
so sach » so sanh, bo sach, co sach
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
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: so sach ty ((nang xa) OR (nang x)) hoi. hieu ve phan tu ((va hanh) or (va thanh)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (nang x)) hoi. hieu ve phan tu ((va hanh) OR (va thanh)) vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) OR (nang x)) hoi. hieu ve phan tu ((va hanh) or (va thanh)) vi su triet".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) OR (nang x)) hoi. hieu ve phan tu ((va hanh) or (va thanh)) vi su triet*.