Perhaps you should try some spelling variations:
xa thanh » ha thanh, ta thanh, gia thanh
va thanh » gia thanh, ban thanh, va tinh
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
doi su » oi su, don su, voi su

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (van xay)) hoi. hieu va cac tuc ((xa thanh) OR (va thanh)) doi su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) or (van xay)) hoi. hieu va cac tuc ((xa thanh) OR (va thanh)) doi su triet~".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (van xay)) hoi. hieu va cac tuc ((xa thanh) OR (va thanh)) doi su triet*.