Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
nang doc » nang luc
xuc van » duc van, luc van, vuc van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang co » nang cao, nang noi, nang hoc
van cau » van dau, van hau, van chat
dai su » dai sua, dai so, dan 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: tu sach ky ((nang co) OR (nang doc)) loi. hieu ((van cau) OR (cao chat)) xuc van hanh dai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang co) OR (nang doc)) loi. hieu ((van cau) or (cao chat)) xuc van hanh dai su triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang co) OR (nang doc)) loi. hieu ((van cau) or (cao chat)) xuc van hanh dai su triet*.