Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
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
qua cac » cua cac
hanh va » hang va, hanh vi
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
ky van » ly van, ty van, ky va

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