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